The Senate bid for Crist, who is among the most prominent moderate Republicans in the nation, comes at a time when the GOP is seeking a new identity in the wake of the 2008 elections. His attempt to win the seat being vacated by retiring Sen. Mel Martinez could play an important role in the debate over the future of the Republican Party.
"Here in Florida, we've shown that when we put people first and work together much can be accomplished, and I intend to bring that same approach to Washington," Crist said in a statement announcing his decision. "That is why, after thoughtful consideration with my wife Carole, I have decided to run for the U.S. Senate."
"If we're offering the same thing as the Democrats, but with different packaging, what's the point in having a Republican Party?" Rubio told Politico. "I'm going to offer Floridians a clear, consistent, authentic small-government choice in the primary."
Crist is the clear favorite in the Republican primary – an April Quinnipiac poll showed him leading Rubio 54 percent to 8 percent – though Rubio is well-liked by conservatives and is positioned to cause problems for the more moderate Crist if he can raise enough money.
Still, national Republicans are unlikely to rally behind Rubio, even if they might prefer him ideologically, because Crist's entry into the race means they won't have to spend as much to defend Martinez' seat. With Democrats poised to secure a filibuster-proof Senate majority if and when Minnesota's Al Franken is seated, Republicans will be fighting hard for every last seat, and they won't want to spend money where they don't have to – particularly in Florida, one of the most expensive states to run a campaign.
U.S. Senator John Cornyn (R-TX), Chairman of the National Republican Senatorial Committee, endorsed Crist not long after his announcement Tuesday morning.
"With his record of reform in Florida, I know that Governor Crist will bring a fresh perspective to Washington in our efforts to fight for lower taxes, less government, and new job creation for all Americans," he said. "Charlie Crist is a tireless advocate on behalf of all Floridians and one of only three Governors who earned an 'A' from the CATO Institute for his efforts to restrain spending and cut taxes last year."
Conservative Republicans may well not be happy with support for Crist from the party establishment as potential GOP standard-bearers jockey for position in a post-Obama world. Crist, who was mentioned as a potential vice presidential candidate for Sen. John McCain in the presidential election, could gain greater prominence as the face of the party during his bid – a troubling prospect for those who would rather see their party hue closer to the ideology of someone like Governors Sarah Palin, Bobby Jindal and Mark Sanford or former GOP presidential candidate Mike Huckabee.