On the Democratic side, there are several possible contenders. Rep. Shelley Berkley has gotten the most attention thus far, but there's a deep bench of candidates holding statewide office who could run as well, including Attorney General Catherine Cortez Masto, Secretary of State Ross Miller, and State Treasurer Kate Marshall.
Despite Harry Reid's decisive win over Sharron Angle last year, the state swung to the GOP side as Reid's own son, Rory, losing a blowout gubernatorial race to Brian Sandoval.
"I would say it's up for grabs," Joseph Valenzano, a communications professor at UNLV told TPM. "The trajectory of the state is kind of all over the map lately -- it went very Democratic in 2008 and very Republican in 2010. I think it's going to be a really close campaign if it ends up being Heller and Berkley."
Democrats are counting on President Obama to drive Democratic turnout back towards 2008 levels. Sen. Reid's own turnout machine also won rave reviews against Angle and Dem officials are hoping to build on it in next year's race as well.