2013 Massachusetts's 5th congressional district special election

A special election for Massachusetts's 5th congressional district took place on December 10, 2013, due to the resignation of Democratic Congressman Ed Markey following his election to the United States Senate in a special election on June 25, 2013. Primary elections were held on October 15, in which Democratic state senator Katherine Clark and Republican Frank Addivinola won their party nominations. State law required that Governor Deval Patrick call a special election between 145 and 160 days after the vacancy became official. On December 10, Clark easily defeated Addivinola with almost 2/3 of the vote, holding the seat for the Democrats. Clark's win marked the 92nd consecutive U.S. House loss by Republicans in Massachusetts since 1996.

Declared

 * Will Brownsberger, state senator
 * Katherine Clark, state senator
 * Peter Koutoujian, Sheriff of Middlesex County and former state representative
 * Martin Long, former member of the Lexington School Committee
 * Paul Maisano
 * Carl Sciortino, state representative
 * Karen Spilka, state senator

Declined

 * Warren Tolman, former state senator

Polling

 * * Internal poll for Katherine Clark Campaign
 * ^ Internal poll for Karen Spilka Campaign

Results
[[File:2013 Democratic special primary in Massachusetts' 5th congressional district by municipality.svg|thumb|Democratic primary results by municipality{{legend|#c88fe4|Clark}}

{{legend|#f2dffc|30–40%}}

{{legend|#dcb7ef|40–50%}}

{{legend|#c88fe4|50–60%}}

{{legend|#b368d9|60–70%}}

{{legend|#9d40cc|70–80%}}{{legend|#73bc84|Koutoujian}}

{{legend|#d6efdcff|30–40%}}

{{legend|#a3d5ac|40–50%}}

{{legend|#008c29|70–80%}}{{legend|#e8bf85|Sciortino}}

{{legend|#e8bf85|40–50%}}{{legend|#db3577|Brownsberger}}

{{legend|#db3577|60–70%}}{{legend|#81d0d0|Spilka}}

{{legend|#daf5f5|30–40%}}

{{legend|#ace1e1|40–50%}}

{{legend|#81d0d0|50–60%}}

{{legend|#53bfbf|60–70%}}

{{legend|#1eafaf|70–80%}}

{{legend|#106666|80–90%}}]]

Declared

 * Frank Addivinola, lawyer and candidate for the 5th congressional district in 2012
 * Mike Stopa, physicist and candidate for Massachusetts's 3rd congressional district in 2010
 * Tom Tierney, actuary and nominee for the 5th congressional district in 2012