Friday, March 6, 2020

Partisanship, education, and income were significant factors in MA presidential primary vote share


The big story out of the Super Tuesday Presidential primaries was the unprecedented Biden surge that put the former Vice President in the strongest position to win the 2020 Democratic nomination. The surge was so strong that it pushed Joe Biden past both Vermont Senator Bernie Sanders and Massachusetts Senator Elizabeth Warren in Massachusetts. Warren and Sanders had been vying for first place in the pre-South Carolina polls, with Biden running a distant third.

I was interested in looking a little deeper at the relative performance of the three major candidates in Massachusetts among different demographic groups to see which types of voters voted for each candidate.

I combined the unofficial city and town election results as reported by the AP and the Boston Globe and joined it together with American Community Survey Census data and results from previous presidential elections to look for relationships.

The city/town comparison is not ideal, in that we lose a lot of interesting variation in the large cities which are aggregated into a single number for each variable, but there was still enough variation to support interesting findings.

The three most significant factors turned out to be the extent of Democratic/Republican partisanship in each municipality as measured by Partisan Voter Index (PVI), the percentage of people with a college degree, and the percentage of people below the poverty line.


Elizabeth Warren had a much higher percentage of votes in more liberal municipalities and Joe Biden had a higher percentage of votes in more conservative cities and towns. Bernie Sanders did marginally better in more liberal areas, but the partisanship score did not explain a significant difference in his performance.

The partisanship score I used was the Partisan Voter Index (PVI) which is an average of the Democratic vs. Republican vote share in the last two presidential elections as compared to the United States as a whole.


Bernie Sanders performed significantly better in cities and towns with a lower percentage of college educated voters, while Elizabeth Warren performed much better in municipalities with a higher percentage of college voters. Education did not make a significant difference in Joe Biden's vote percentage.


The income level in a city or town made a measurable difference to Sanders's and Biden's electoral performance, while not factoring a great deal in Warren's vote share. Bernie Sanders performed better in areas with a larger percentage of people below the poverty line, while Biden performed better in more affluent municipalities.

Thursday, November 1, 2018

Which Massachusetts cities and towns are getting more Republican or Democratic?

When comparing presidential margins, it comes down to Trumpiness

We often think of the partisan lean of a district, town, or city as a fairly static characteristic. One of the common metrics to use for measuring partisan lean of a region is the Partisan Voter Index or PVI which looks at the Democratic/Republican margin averaged over the last two presidential cycles, compared to that of the country as a whole.

But partisan lean is not a static characteristic. Voters in a particular area sometimes vote for a Democratic candidate in one presidential election and a Republican in the next. Voters also move in and out of districts, cities, and towns changing the voting behaviors.

This article looks at the partisan shifts in Massachusetts cities and towns by comparing the Democratic margin in the 2008 Obama vs. McCain election to the margin in the 2016 Clinton vs. Trump election as a way of judging which cities and towns have gotten more Democratic, and which have gotten more Republican. I also look at what demographics might explain these shifts.

Here is a map of Massachusetts cities and towns with colors indicating the partisan voting shifts between 2008 and 2016 presidential elections.

MA presidential vote shifts from 2008 to 2016 (click for interactive map)
Map of MA presidential vote margin shifts from 2008 to 2016

You can see some geographic clustering, but are there other demographic factors that help to explain the shifts?

A regression analysis points to two demographic variables that were responsible for 73% of the variation in the partisan voter shift—they were the percentage of residents that did not attend college, and the percent of non-hispanic white residents. (The demographic data was from the 2016 American Community Survey from the US Census Bureau.)

Table of MA cities and towns with biggest Democratic shifts from 2008 to 2016

The Massachusetts municipalities that shifted the most towards the Democratic side between 2008 and 2016 are primarily in the affluent Metrowest suburbs of Boston, but also include North Shore towns like Hamilton an Manchester-by-the-Sea and the South Shore towns of Cohasset and Hingham. The two towns with the biggest Democratic shifts were Sherborn and Dover.

Table of MA cities and towns with biggest Republican shifts from 2008 to 2016

The cities and towns with the biggest Republican shifts are primarily in West Central and Western Massachusetts although there is also a cluster on the South Coast including Somerset, Fall River, Westport, Acushnet, and Fairhaven. The town with the largest shift from Obama towards trump is the small town of Monroe on the Vermont border.

Table of MA cities and towns with lowest college education

The importance of the race variable in the regression is shown by this table sorted by college educational attainment. While most theses cities and towns shifted Republican, the 8 that shifted the Democratic direction show high percentages of minorities. A regression model with only the education component only predicts 60% of variation in the partisan shift, rather than the 73% of the two variable model.

The education component identified by the regression model is consistent with other studies that have been done on shifts from Obama to Trump, notably this Nate Silver Fivethirtyeight piece: Education, not income, predicted who would vote for Trump, although the Massachusetts model benefits more by using the race variable.

The research behind this post was used by Adam Reilly for a WGBH All Things Considered piece.

Here is the full list table of partisan shift for each of the 351 cities and towns of Massachusetts. You can click on the table to open a searchable Google Sheet with the data.

MA cities and towns partisan shift table

Friday, August 31, 2018

An overview of Massachusetts 3rd Congressional district and primary candidates

Results of the September 4 primary will likely determine the race

On August 9, 2017 Niki Tsongas shocked the Massachusetts political world by announcing she would not seek another term in the U.S. House for the Massachusetts 3rd District. Tsongas had represented the district after winning a special election to replace Marty Meehan in 2007.

The retirement announcement set of a flurry of exploratory activity and as many as 19 candidates have been in and out of the race. According to the Secretary of the Commonwealth, there are 10 Democratic candidates and one Republican candidate who will be on the primary ballot on September 4, 2018. Based on the partisan lean of the district and the current political climate, it is very likely that the winner of the Democratic primary will go on to succeed Tsongas in the House.

The District

The Massachusetts 3rd Congressional District extends from Haverhill, Methuen, Lawrence, Andover, and Lawrence in the Merrimack Valley, across to Ashburnham, Gardner, and Winchendon in North-Central Mass., and down to Concord, Subury, and Marlborough in Boston's Metrowest region.

The 3rd District is the third-most conservative congressional district in Massachusetts with a PVI of D+9, meaning that it is 9 points more Democratic than the rest of the country, measured by an average of the last two presidential elections.

MA 3rd City/Town PVI (click for interactive map)
MA 3rd City/Town PVI

There is a wide variation in the partisan lean of the cities and towns in the 3rd District.

The city of Lawrence is the most Democratic in the district at D+33 putting it just above the 97th percentile for Massachusetts cities and towns. Townsend and Ashby are two of the most Republican towns in the Commonwealth at R+7, around 95th percentile in the other direction. The municipality with the district's median PVI is Westford at D+5.

The Republican-leaning towns are primarily distributed along the New Hampshire border and then creeping down into North Central Mass. in Lunenburg, Lancaster, and Winchendon.

MA 3rd City/Town PVI Table

There is also a wide variation in population and number of active voters in the cities and towns of the district. I am using the number of voters from each of the municipalities in the 2014 mid-term election as an estimate of the number of 2018 voters.

MA 3rd City/Town 2014 votes (click for interactive map)
MA 3rd City/Town Votes Map

MA 3rd City/Town Votes Table

Of the top 9 vote-producing municipalities, only Marlborough is not in the northeastern region of the district.

In the following map, the 10 municipalities in the northeast area colored in orange accounted for 51% of the district votes in 2014, while the remaining 27 municipalities in yellow accounted for 49%.

MA 3rd City/Town vote distribution
MA 3rd City/Town Northeast Votes Map

MA 3rd City/Town median family income (click for interactive map)
MA 3rd City/Town median family income map

In terms of demographics, the Massachusetts 3rd district is home to Sudbury, one the Commonwealth's richest towns with a median family income of $186,507. It is also home to Massachusetts's poorest city in Lawrence, with a median family income of $36,073. The town of Pepperell has the median median-family-income for the district at $94,625.

The richest towns are clustered in the Metrowest area of the district, but extend up through Groton. Andover is the only upper-income municipality in Essex County. The smaller western towns and Fitchburg are on the lower end of the median family income spectrum.

MA 3rd City/Town median family income table

The Candidates

There are 10 Democrats and one Republican on the September 4 primary ballot.

Table of candidates for the Massachusetts 3rd District

That table is sorted by the amount of contributions to the campaign, a simple but not always accurate judge of candidate viability. I have separated out candidate campaign loans which can inflate total receipt numbers for candidates like Beej Das who have loaned their campaigns much more than they have raised.

It is unlikely that a candidate that raises zero dollars in a very competitive primary like this one is putting in the necessary effort to earn more than a token amount of votes, especially given the resources of those who are raising over a million dollars to reach out through a paid field staff and advertising.

There have been two public polls of the race. The first showed Rufus Gifford in the lead, but with whopping 59% not having a preference. In the second poll, the no preference was down to 29%—still quite high. It showed Dan Koh on top with 19%, followed by Gifford and Barbara L'Italien, both with 13%.

MA 3rd Poll Results Table

The front-running candidates have been hammering the airwaves with TV ads, inundating mail boxes with mailers, and knocking doors. It is pretty easy to identify the top five finishers, but very difficult to predict their finishing order.

Wednesday, December 6, 2017

Over-performance in Fitchburg pushed Tran over the top in Worcester and Middlesex special election

Zephir slightly over-performed compared to a modeled result in most other towns

Republican Fitchburg City Councilor Dean Tran defeated three other opponents, including Democratic Leominster City Councilor Sue Chalifoux Zephir, to replace State Senator Jen Flanagan in the Worcester and Middlesex senate district by a margin of 607 votes (unofficial results).

Tran's victory was mainly due to a staggering 19 point victory in his home city of Fitchburg, which has a strong lean towards Democrats in most elections. Fitchburg has a Partisan Voter Index (PVI) of D+9. Our state legislative regression model predicted a Democratic vote share of 56% for an open seat in a non-presidential year.

Worcester and Middlesex special election results vs. PVI chart

Sue Chalifoux Zephir out-performed the model in most of the other municipalities, including an 11 point over-performance in the much-smaller town of Sterling, and kept it reasonably close in the others.

Zephir would have stood a better chance if she could have built a home field advantage in Leominster, similar to Tran's in Fitchburg, but fellow City Councilor Claire Freda came within range of Tran and Zephir with over a thousand votes, by far Freda's strongest showing in any municipality. It seems that Freda's success in Leominster prevented Zephir from running up the numbers in the largest vote-producing city in the district.

Senator-elect Tran will serve out the rest of the current term and will be up for re-election next November, 2018. He will have the advantage of incumbency, but will face a much larger Democratically motivated electorate in a highly-charged mid-term election.

Tuesday, December 5, 2017

A look at the Worcester and Middlesex State Senate special election

Another classic swing district special election

There is a special election today to fill the vacant Worcester and Middlesex state senate seat, left vacant by former Senator Jen Flanagan who left to take a seat on the newly-created MA Cannabis Control Commission. There are four candidates vying for the seat: Leominster City Councilor and Democratic nominee Sue Chalifoux Zephir; Fitchburg City Councilor and Republican nominee Dean Tran; Green-Rainbow nominee Charlene DiCalogero; and Leominster City Councilor Claire Freda, who is running as an independent.

The District

The Worcester and Middlesex is a classic swing district with a Partisan Voter Index (PVI) of D+2. While it has been held by a Democrat since 1991, a slightly different configuration of the district was held for many years by Republicans Mary Padula of Lunenburg and Robert A. Hall of Fitchburg.

(Click here for an interactive version of the map.) Worcester and Middlesex Senate District Precinct PVI map

The precincts range from the D+22 Fitchburg 5-B to the R+10 Townsend 1st, which is in the top 20 most Republican precincts in the state.

Worcester and Middlesex District Precinct PVI chart

The cities of Clinton, Gardner, and Fitchburg are fairly blue along with the towns of Berlin and Bolton, while the remaining towns of Lancaster, Lunenburg, Sterling, Townsend, and Westminster, with Townsend leading the way with an overall PVI of R+7.


Democrat Sue Chalifoux Zephir raised and spent over twice as much money as GOP candidate Dean Tran across the pre-primary and pre-election periods, while independent candidate Claire Freda and Green-Rainbow candidate Charlene DiCalogero were off the pace by an order of magnitude.

Worcester and Middlesex fundraising chart

Fundraising and spending are not determining factors, but they are a strong indication of candidate strength.

Special Election

The race is essentially a toss-up in our model, with the slightest advantage given to the GOP in a non-presidential election year without an incumbent, although a Democratic win by 10 points could easily happen within the model's 90% confidence interval.

While 3rd party and independent candidates, on average, play a very small role in most races with Democrats and Republicans winning the lion's share of the votes, they can play an important role when the margins are very small. While I believe that Sue Chalifoux Zephir will dominate among progressives and Democrats, Claire Freda—a well-known Leominster City Councilor—was endorsed by the Fitchburg Sentinel, and has a chance to take some votes from the major party candidates.

The state party establishments have been all-in on this race with every major Massachusetts Democrat putting in work for Zephir, while Charlie Baker has worked hard for Tran, and the state GOP has delivered some last minute attack ads on Zephir in the closing day of the race.

There is no easy pick for the winner of the Worcester and Middlesex special election, with the race coming down to a slight GOP lean in the model vs. strong fundraising by Zephir and a seemingly pro-Democratic atmosphere indicated in several special elections so far this year.

Monday, November 6, 2017

Polls and preliminary data point toward a Walsh victory in Boston mayoral race

A remarkably consistent margin has separated Walsh and Jackson in polls and preliminary voting

All of the public data measuring voter preference in the 2017 Boston mayoral race show a gap in the low thirty point range, pointing toward a large victory by incumbent Marty Walsh over challenger City Councilor Tito Jackson on Tuesday, November 7.

There have been three publicly released polls of the race conducted by MassINC, Emerson, and Suffolk, all showing Walsh/Jackson margins in the 31 to 36 point range. The September 26 preliminary election showed a Walsh/Jackson margin of 33 points.


Preliminary result geography

The precinct-by-precinct results from the preliminary show Walsh winning 210 of 254 (83%) of the precincts.

(Click here for an interactive version of the map.)
Map of Boston preliminary results by precinct

A look at the preliminary results by neighborhood/planning district show Jackson winning Roxbury by 9 points, while Walsh won all other districts with the largest margin coming in at a whopping 71 points in South Boston.

(Click here for an interactive version of the map.)
Map of Boston preliminary results by neighborhood

Walsh had a small victory over Jackson in Jackson's own City Council District 7, winning 51% of the two-way Walsh/Jackson voters.

Given the consistency of the overall margin in the preliminary results and the polls, it would be a remarkable upset and an indication in some serious polling failures if Marty Walsh is not easily re-elected on November 7.

Sunday, October 15, 2017

All signs point to a close outcome in Tuesday's Bristol and Norfolk state senate special election

Bristol and Norfolk is a prototypical swing district

Heavy hitters from the Massachusetts Democratic and Republican parties have gotten involved in the closing days of the special election campaign to take the open Bristol and Norfolk State Senate seat, previously held by Senator James Tmility (D-Walpole). The candidates will need all the help they can get in a district that could easily go to a Democrat or a Republican.

The resignation of Timilty to take the position of Norfolk County Treasurer has led to a scramble by Democratic, Republican, and Independent candidates vying for the open seat in an October 17. The candidates on the ballot will be Paul Feeney, a progressive Democrat from Foxborough, Jacob Ventura, a conservative Republican from Attleboro, and former TV news reporter Joe Shortsleeve of Medfield who is running as an Independent.

Republican Governor Charlie Baker gave his support to Ventura in an October 7 visit to Attleboro, while Senator Elizabeth Warren endorsed and canvassed with Feeney on Sunday, October 15. Feeney had a similar event with Congressman Joe Kennedy on September 23rd.

Swing District

The Bristol and Norfolk District, held by Democrat Timilty since 2005, is the definition of a Massachusetts swing district with a PVI rating (an average of the last two presidential races compared to the U.S. average) of D+2. This makes it the fifth-most Republican state senate district in Massachusetts.

There are two Democrats elected in more Republican state senate districts: Marc Pacheco in the 1st Plymouth and Bristol (EVEN), and Anne Gobi in the most-Republican Worcester, Hampden, Hampshire, and Middlesex District (R+4). There are three Republican State Senators in more Democratic districts: Patrick O'Connor (Plymouth and Norfolk—D+2), Bruce Tarr (1st Essex and Middlesex—D+3), and Donald Humason (2nd Hampden and Hampshire—D+7).

Our Mass. Numbers regression model, which looks at district PVI and incumbency status, gives an edge to a Democrat in a D+2 race without an incumbent.

The Municipalities

There are seven full towns in the Bristol and Norfolk District—Foxborough, Mansfield, Medfield, Norton, Rehoboth, and Walpole—and parts of the town of Sharon, and the city of Attleboro.

Table of Bristol and Norfolk municipalities including PVI and percent of the vote

The partisanship of the municipalities range from R+6 in Rehoboth to D+19 in the district's Sharon precincts. Walpole provides the most votes in the last two presidential elections, followed by Mansfield, the Attleboro precincts, and Foxborough.

Bristol and Norfolk Precinct Map

(Click to view interactive map.)
Bristol and Norfolks precinct map

Only Medfield and the Sharon precincts are completely Democratic with respect to PVI, and Rehoboth is the only municipality with completely Republican precincts. The remaining municipalities have both Democratic and Republican precincts.

Fundraising and Expenditures

Campaign fundraising strength is another gauge of candidate strength. Democrat Paul Feeney has outraised and outspent his opponents, raising $76,706 and spending $62,365 as reported on the pre-primary and pre-election reports.

Republican Jacob Ventura raised $39,480 during the same period and spent $40,275, while Independent candidate Joe Shortsleeve raised $5,765 and spent only $3,383.

A wild-card on the spending side is a Republican special interest committee called Jobs First, which has spent $22,772 dollars, mostly on attack ads against Feeney, but also on an a positive ad for Ventura.

Turnout/Third-Party Effects

Special elections normally have very low turnout with only the most motivated voters getting to the polls. The demographic of those hard-core voters normally trends towards older and more conservative, giving a bit of an advantage to Republicans. However, this can be exacerbated or overcome by a strong voter contact and get-out-the-vote efforts by candidates.

It is unclear how Joe Shortsleeve, running as an Independent, will impact Tuesday's vote. Shortsleeve is a bit of enigma, having voted for Trump for President, but saying he will caucus with Democrats in the Senate if elected. Shortsleeve was attacked, along with Feeney, in a Republican mailer, seemingly trying to shore up conservative support for Ventura. However, it is unlikely that Shortsleeve will get too many progressive votes if they know that Shortsleeve supported Trump in 2016.

The new Senator from the Bristol and Norfolk District will likely be the candidate who runs the best voter contact and get-out-the-vote operation on October 17. We could very well end up with another 20 or 100 vote nail-biter.