Going into the 2012 elections, the Senate consists of 53 Democrats and 47 Republicans.
A total of 33 of the 100 Senate seats are up for election in 2012. Of those 33 seats, Democrats hold 23 seats and Republicans hold 10.
To maintain majority control of the Senate, the Democrats need to win 21 of the 33 seats up for grabs. The Republicans gain control of the Senate by winning 14 of the contests.
As many as 10 incumbent Senators are not running for reelection. The list includes Olympia Snow (R) Maine, Jim Webb (D) Virginia, and Kay Bailey Hutchison (R) Texas.
In 2006, Jim Webb narrowly defeated incumbent George Allen to win the Virginia seat. Webb’s decision not to run in 2012 opens the door for another hotly-contested election in Virginia.
The Democratic candidate is former governor Tim Kaine, who was unopposed for the party’s nomination. Kaine served one term as Virginia’s governor from 2006 to 2010. Previously, Kaine had served as mayor of Richmond, Virginia, and as the state’s Lieutenant Governor.
The Republicans won’t determine who their candidate is until the June 12 primary vote. Four candidates are vying for the nomination, but George Allen is the heavy favorite to win it. Allen served from 2000 to 2006 in the U.S. Senate. He served one term as governor of Virginia from 1994 to 1998.
Democrat Claire McCaskill of Missouri and Republican Scott Brown of Massachusetts are two of the incumbents who face tough reelection bids.
Missouri is traditionally a Republican state while Massachusetts is staunchly Democratic. In 2008, McCaskill defeated then-incumbent Jim Talent, becoming the first woman elected to the U.S. Senate from Missouri.
McCaskill’s supporters say she has been the number one fighter in the Senate against earmarks – funds used to support projects as favors for members of Congress. Opponents found out about unpaid taxes on- and improper use of – her private airplane. McCaskill called the entire episode “embarrassing” and paid the taxes, but the airplane episode is sure to be part of the campaign.
Scott Brown won a 2010 special election to succeed the late Massachusetts Senator, Ted Kennedy. Brown, Massachusetts’ first Republican Senator since 1972, now is running to win a full six-year term. His opponent has yet to be determined. Elizabeth Warren and Marisa DeFranco are running to win the Democratic nomination for the Senate race. The Massachusetts primary is scheduled for September 6.