Eye on 2010

Party operatives cheered Crist's decision to eschew a bid for a second term as the state's chief executive and instead run for U.S. Senate. Crist supporters view the governor as the most electable GOP candidate in the competitive state of Florida.

Polls show Crist easily besting Rubio in hypothetical primary match-ups. A Quinnipiac University poll conducted June 2-7 found Crist led Rubio 54 to 23 percent among registered Republicans.

But conservatives have cried foul over the decision by the NRSC and other officials to get involved in the GOP primary.

Marco Rubio

"I wanted to get the ball rolling today and I think the more of us who jump in, the more comfortable it's going to be for people to move the way their conscience guides them," DeMint said at a press conference with Rubio on Capitol Hill.

Earlier this year, DeMint told moderate Republican Sen. Arlen Specter of Pennsylvania he would back Specter's conservative GOP primary opponent, Pat Toomey, over Specter in 2010. Five days later, Specter announced he would change his party affiliation to Democrat.

In the 2008 cycle, DeMint established a leadership political action committee, the Senate Conservatives Fund, to financially support conservative candidates such as Bob Schaffer in Colorado and Steve Pearce in New Mexico.

The contest is an open seat race. Current Republican Sen. Mel Martinez is retiring in 2011.

On the Democratic side, Democratic Rep. Kendrick B. Meek currently leads the field but statewide remains largely unknown to many voters.

CQ Politics rates the race Leans Republican.

To see how the 2010 Senate races are shaping up, check out the CQ Politics' election map.