Massachusetts Senate

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Massachusetts House / Massachusetts Senate

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2020 Election Update

Heading into the 2020 election, Democrats controlled the Massachusetts Senate 36 to 4. Democrats flipped 1 seat (SD Worcester and Middlesex) for a net gain of 1 seat. Democrats now control the chamber 37 to 3.

The below table shows 2020 and 2018 election results for the Massachusetts Senate. The LDI scores are for the 2020 cycle. EveryDistrict will release new scores and district rankings after the redistricting process.

2018 Election Update

After the 2016 election, Democrats controlled the Massachusetts State Senate 34-6. In 2017, Republicans flipped a Democratic-held seat, cutting the Democratic majority to 33-7. In the 2018 election, Democrats flipped one seat to bring their majority back to 34-6.

Democrats flipped Norfolk, Bristol, and Middlesex.

Democrats flipped two districts in 2020 special elections (Second Hampden and Hampshire, Plymouth and Barnstable), growing their majority to 36-4.

Understanding the Map

EveryDistrict’s Legislative District Index (LDI) is the gold standard of state legislative competitiveness. Our LDI ranks state legislative districts on a scale from 100 to -100, using statewide elections data. Districts with a score of 100 would vote for statewide Democratic candidates by an average of 100 points (with the Democratic candidate receiving 100% of the vote); districts with a score of -100 would vote for statewide Republican candidates by an average of 100 points (with the Republican candidate receiving 100% of the vote). For a more realistic example, a district with a score of 10 would vote for statewide Democratic candidates by an average of 10 points (meaning we would expect the Democratic state legislative candidate to win with 55% of the vote compared to the Republican winning 45% of the vote).

After the 2018 election, EveryDistrict reviewed and enhanced our LDI system, improving the accuracy of the metric with new methodologies and the most recent electoral data.

For more information about EveryDistrict’s LDI, please click here.