U.S. Senate elections, 2010

United States Senate elections, 2010

← 2008 November 2, 2010 2012 →
34 of the 100 seats of the U.S. Senate, plus 3 two mid-term vacancies 51 seats needed for a majority
Majority party Minority party   Leader Harry Reid Mitch McConnell Party Democratic Republican Leader's seat Nevada Kentucky Seats before 57 41 Seats after 51 47 Seat change 6 6 Popular vote 29,110,733 32,680,704 Percentage 44.0% 49.4% Swing 7.9% 4.9% Seats up 19 18 Races won 13 24   Third party   Party Independent Seats before 2 Seats after 2 Seat change Seats up 0
Democratic hold   Republican gain   Republican hold
Majority Leader before election Harry Reid Democratic Elected Majority Leader Harry Reid Democratic

Harry Reid
Democratic

Harry Reid
Democratic

Elections to the United States Senate were held on November 2, 2010 for 37 of the United States Senate's 100 seats. (A special election on January 19, 2010 in Massachusetts was held earlier in the year.) Thirty-four of the elections were for six-year terms to the Senate's "class three", while the other three elections were special elections for shorter terms. Of the 37 elections, 19 featured incumbent Democrats (7 of whom retired or were defeated in the primary) and 18 featured incumbent Republicans (eight of whom retired or were defeated in the primary).

After the previous elections (in 2008), the Senate was composed of 58 Democrats, 40 Republicans, and 2 independents who caucused with the Democrats.

Republicans won four seats held by retiring Democrats (Illinois, Indiana, North Dakota, and Pennsylvania) and Republicans defeated two incumbent Democrats (Blanche Lincoln of Arkansas and Russ Feingold of Wisconsin), for a total gain of six seats. This was the largest number of Republicans gains since the 1994 elections and also the first time since that election that Republicans successfully defended all of their own seats. This was the fourth consecutive election of "class 3" senators where Democrats failed to gain seats and the third consecutive mid-term election held in a president's first term where Republicans picked up seats.