After yesterday’s special primary elections, only three of the five winners will face opposition in their respective general elections. A quick glance at party registration statistics and past election results helps explain why.

Of the five special election districts, the 13th Suffolk and 2nd Suffolk are the two farthest from reach for Republicans, and neither has produced a Republican opponent for the general. In these districts, Democrats have won the three statewide elections since redistricting by around 40 percent, margins landing these districts in the top third of most Democratic house districts in the state. (Quick side note: These figures come from our soon-to-be published house rankings, similar to the Senate rankings we recently published.)

On the other end of the spectrum, the 4th Hampden is the most conservative of the districts that voted yesterday. Republicans have won there by an average margin of 11 points in recent statewide elections, so it is no surprise this district will be contested in the general election. The race is to replace former Republican Representative Donald Humason, who won the two opposed elections he has faced since 2002 by over 30 points.

Somewhere in the middle is the 16th Suffolk, where Revere Democrat RosaLee Vincent will face Chelsea Republican Todd Taylor on April 1. The Democratic registration gap there is still a formidable 40 points, but the Democratic margin of victory is 20 points, half of the other Suffolk Districts. Still, winning the district will be a challenge for the Republicans.

District Previous party held seat Party Reg Gap  Registration Ranking  (out of 160) Average Dem Margin 2012-13 Margin ranking (out of 160) Dems running Reps running
13th Suffolk D 48% 16 43% 29 5 0
2nd Suffolk D 39% 36 36% 44 3 0
16th Suffolk D 40% 28 20% 61 3 1
4th Hampden R 9% 138 -11% 132 1 1

On the State Senate side, Jason Lewis won the Democratic nomination in the 5th Middlesex district and will face Melrose alderman-at-large Monica Medeiros.  The district leans Democrat, but it is near the middle of the pack in terms of Democratic party registration advantage and only voted for Ed Markey by 6 points in the 2013 special election.

District Previous party held seat Party Reg Gap Registration Ranking (out of 40) Average Dem Margin 2012-13 Dem Margin ranking (out of 40) Dems running Reps running
5th Middlesex D 25% 21 14% 14 3 1

Correction: An early version of this post incorrectly stated that Democrat Jason Lewis faced no Republican opponent in the general election for State Senate 5th Middlesex district. In fact, Melrose alderman-at-large Monica Medeiros won the Republican primary unopposed and will be on the ballot for the general election. As a result, three, not two, of the five special elections will have both Republican and Democratic candidates. We apologize for the error.