This November’s midterm elections may decide the balance of power in the United States Senate.

Here are twelve key races to watch on election night:

Alaska:

Incumbent: Sen. Mark Begich (D), first elected in 2008, former Mayor of Anchorage.

Challenger: Dan Sullivan (R), former Alaska Attorney General & former Commissioner of the Alaska Department of Natural Resources.

RCP average: Sullivan +4.4 percent

Arkansas:

Incumbent: Sen. Mark Pryor (D), first elected in 2002, former Arkansas Attorney General & State Representative.

Challenger: Rep. Tom Cotton (R), currently serving Arkansas’ fourth congressional district in US House.

RCP average: Cotton +5.5 percent

Colorado:

Incumbent: Sen. Mark Udall (D), first elected in 2008, former US Representative & Colorado State Representative.

Challenger: Rep. Cory Gardner (R), currently serving Colorado’s fourth congressional district in US House, former Colorado State Representative.

RCP average: Gardner +3.8 percent

Georgia (Open Seat):

Candidate 1: Michelle Nunn (D), businesswoman

Candidate 2: David Perdue (R), businessman

RCP average: Purdue +0.8 percent

Iowa (Open Seat):

Candidate 1: Rep. Bruce Braley (D), currently serving Iowa’s first congressional district in US House.

Candidate 2: State Sen. Joni Ernst, currently serving Iowa’s 12^th Senate district in Iowa Senate.

RCP average: Ernst +2.5 percent

Kansas:

Incumbent: Sen. Pat Roberts (R), first elected in 1996, former US Representative.

Challenger: Greg Orman (I), businessman

RCP average: Tie

Kentucky:

Incumbent: Sen. Mitch McConnell (R), first elected in 1984.

Challenger: Alison Lundergan Grimes (D), currently Kentucky Secretary of State.

RCP average: McConnell +4.4 percent

Louisiana:

Incumbent: Sen. Mary Landrieu (D), first elected in 1996, former Louisiana Treasurer & State Representative.

Challenger 1: Rep. Bill Cassidy (R), currently serving Louisiana’s sixth congressional district, former Louisiana State Senator.

Challenger 2: Rob Maness (R), retired U.S. Air Force Colonel.

RCP average: No average calculated between all candidates. In November “jungle primary,” Landrieu leads, in December runoff, if needed, Cassidy leads.

Michigan (Open Seat):

Candidate 1: Rep. Gary Peters (D), currently serving Michigan’s 14^th congressional district, former Michigan State Senator.

Candidate 2: Terri Lynn Land (R), former Michigan Secretary of State.

RCP average: Peters +9.4 percent

New Hampshire:

Incumbent: Sen. Jeanne Shaheen (D), first elected in 2008, former New Hampshire Governor & State Senator.

Challenger: Scott Brown (R), former Massachusetts US Senator, State Senator & State Representative.

RCP average: Shaheen +2.6 percent

North Carolina:

Incumbent: Sen. Kay Hagan (D), first elected in 2008, former North Carolina State Senator.

Challenger: State Rep. Thom Tillis (R), currently serving as North Carolina Speaker of the House.

RCP average: Hagan +2.0 percent

South Dakota (Open Seat):

Candidate 1: Larry Pressler (I), former US Senator and US Representative.

Candidate 2: Mike Rounds (R), former South Dakota Governor and State Senator.

Candidate 3: Rick Weiland (D), businessman, former Advisor to former Sen. Tom Daschle.

RCP average: Round +9.8 percent

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