Thursday, November 15, 2012

How Democratic or Republican is my town?

A partisan ranking of MA municipalities from P-Town to Lynnfield


We often hear people say things like "Central Massachusetts is getting more conservative" and "Western Massachusetts is really blue" when discussing elections and politics. But what can we say from a quantitative point of view about the Democratic or Republican tendencies of various geographic areas of the Commonwealth?

While it is possible to look at the partisan voter registration records in each municipality, Massachusetts allows voters to register as unenrolled, and a majority of residents now register without party affiliation. A better gauge of the Democratic/Republican breakdown in a geographic area is the difference between the number of Democratic and Republic votes in actual elections.

I have collected the results of the statewide elections for Governor, Senator and President from 2006 through 2012 and averaged the difference between the percentage of the vote won by the Democrat, and the percentage of the vote won by the Republican. The results give an estimate of the Democratic/Republican lean of a municipality, with a large positive number indicating a larger percentage of Democratic votes, and a negative number indicating a greater percentage of Republic votes.

First the map:


We can see Western Massachusetts, the Boston Metropolitan Area and other urban areas, the tip of Cape Code, and the Islands show strong Democratic tendencies in statewide elections. Central Massachusetts, parts of the North Shore, and Southern Massachusetts—from Tolland in the west to Dennis in the east—are much more Republican.

Looking at a ranking of municipalities from most Democratic to most Republican we also see that, while there are only slightly more municipalities that have a Democratic lean (186 vs. 165), the margins are much higher on the Democratic side. The most Democratic town in Massachusetts by our measure is Provincetown with Democratic candidates receiving 73% more of the vote on average, while in the most Republican town of Lynnfield, a statewide Republican candidate will only receive 28% more of the vote than her Democratic rival, on average. The transitions between more Democratic and more Republican areas are fairly smooth with islands of blue explained primarily by population density.

There are plenty of Republican-leaning towns in Massachusetts, but there is still a considerable Democratic slant for statewide candidates in the Commonwealth. A subsequent article will examine what these statewide municipal rankings imply about various Massachusetts legislative districts.


  • Searchable spreadsheet with percentages and rankings
  • Full map and data set

    And an alphabetical listing by municipality name:

    6 comments:

    1. Very cool! I think something went wrong in the data analysis for North Andover, though...

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    2. Michael, you were absolutely right. There were some off-by-one issues related to the towns starting with "North" that I have fixed in the map and the charts. Thanks for the heads-up.

      -Brent

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    3. This is very interesting and thanks for gathering, but would it be more useful to use a PVI model here where you would look at performance relative to the statewide average? I.e., if Candidate A beats Candidate B by 10 points but ties in the Town, then Town's PVI is B+10.

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    4. Would love to see if there was any kind of movement because of the most recent special and the upcoming governors. It would be very good for tracking which commnities are trending more republican or more democratic.

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    5. Jim, I am definitely planning on doing an update soon. I have already run the reports for the 2012 Presidential and Senate results for each town, State Rep., State Senate, and Congressional district, and I will be doing posts to summarize over the next weeks.

      In order to compare the old results with the new, I would need to do something like paddynoons suggests above, normalizing each race to the state average, in order to account for differences based on candidate. There is a tradeoff between being able to use the number to represent average Democratic advantage vs. being able to do comparisons across different time periods.

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    6. I live in Lynnfield and I am a democrat, help me

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