Dick Cheney decided to make a splash in Florida today by endorsing Marco Rubio over Charlie Crist in the GOP primary for the US Senate.  Cheney explained that Crist can’t be trusted to remain firm on principle, and that Floridians need a strong conservative leader:

Former Vice President Dick Cheney is endorsing Marco Rubio in Florida’s GOP Senate primary, saying Gov. Charlie Crist can’t be trusted to stand up to President Barack Obama’s agenda.

It’s the latest high-profile endorsement for Rubio. Cheney called him a strong conservative leader.

Rick Klein at ABC’s The Note tweeted this quote from the former VP: “”Congress is already overflowing with politicians who need pollsters to tell them what to think.” Crist’s sudden Hamlet act on an independent run has left him open to this criticism, and he should expect more of it between now and the April 30th deadline for filing candidacy papers.

Crist could, of course, hope that support from conservatives like Cheney and Sarah Palin would marginalize Rubio. Rasmussen’s latest survey of likely voters in Florida suggests that Crist might have a long wait for that:

The latest Rasmussen Reports poll of Florida voters finds that 37% would vote for GOP frontrunner Marco Rubio, 30% for Crist and 22% for the likely Democratic nominee Kendrick Meek. That’s much closer than a month ago when Rubio had a 17-point advantage and Crist was in third place.

In a two-way race, both Rubio and Crist hold solid leads over Meek. Rubio now leads among Republicans and unaffiliated voters with Crist in second. Among Democrats, Meek earns 46% support, while Crist picks up 33% of the Democratic vote.

Meek leads among voters under 30, Crist leads among 30-somethings, and Rubio leads among those 40 and older.

The crosstabs show just how difficult this will be to pull off. To no one’s great surprise, Rubio wins Republicans in a three-way race, but he also wins independents, 40-28 over Crist, with Meek getting just 18%. Rubio wins the male vote easily, 45/31/16, but also edges out Crist and Meek with women, 30/28/28.

Interestingly but perhaps not terribly surprisingly, Rubio’s success depends on the intensity of disapproval for Barack Obama. He wins 67% of those who strongly disapprove of Obama, but only 22% of those who “somewhat disapprove.” Crist gains 54% of that demographic. Crist also leads among those who “somewhat approve” of Obama, 45% to Meek’s 38% and Rubio’s 10%, but Meek gets the edge among those who strongly approve of Obama, 44% to Crist’s 35% and a near-zero for Rubio.

What does it say about Crist that those who strongly approve of Obama’s performance still support Crist so strongly? Better yet, what does that say about Kendrick Meek? Small wonder he trails so badly in all permutations of this race.