Republicans will have former Rep. Artur Davis speaking at their national convention this week — the man who served as Barack Obama’s national co-chair in 2008 and seconded his nomination at the Democratic convention that year.  Democrats now have their answer, a prominent former Republican officeholder who will speak at the Democratic convention in Charlotte next week:

Florida’s former Republican Gov. Charlie Crist will be a speaker at the Democratic National Convention.

An official with President Barack Obama’s campaign said Sunday that Crist will speak at next week’s convention in Charlotte, N.C., but the day hasn’t been worked out.

Actually, this is a great swap … for Republicans.  Crist is rumored to have ambitions to seek his old job back on the Democratic ticket in 2014, but he hardly impressed Floridians with his sour-grapes moves in the 2010 Senate election.  Instead of acknowledging his loss in the primary to Marco Rubio, Crist decided to run as an independent. In fact, at perhaps more than one point, he tried to push Democrat Kendrick Meek out of the race and get Obama’s endorsement.

How did that work out?  Rubio nearly won a majority at 48% in a three-way race, with Crist — the sitting governor at the time — finishing a distant second at 30%. Democrat Kendrick Meek only got 20% of the vote.  Crist lost even among independents, 51% of whom backed Rubio to Crist’s 38%.

Now, with Florida on the line as a swing state, Obama will feature a politician that could only get 30% of the vote in a Senate race while serving as governor to endorse him on national TV.  It makes for good optics on TV to give an apostate the floor (as it does for the GOP with Davis), but they’re hitching their wagon to a fallen star in terms of Florida.

Update: Paul Mirengoff explores the “sour grapes” factor even further:

The fact that Crist lost gives rise to the suspicion that his endorsement of Obama represents sour grapes. This suspicion gains strength from the fact that Crist in the past has been quite critical of Obama. By contrast, Miller turned against his fellow Democrats for coherent ideological reasons — Miller was moderate to conservative. Similarly, Lieberman endorsed McCain because the two had long been closely aligned on foreign policy and national security issues, and because Lieberman sensed, correctly, that Obama’s views on these matters did not comport with the Lieberman/McCain approach.

Unfortunately, there is one more difference between Crist and Miller/Lieberman — Crist comes from a state that the Republicans probably must win. Moreover, as noted, Crist pulled in 30 percent of the Florida vote in his 2010 Senate race. In the context of Crist’s career, that showing was fairly pathetic. But in the context of an extremely tight presidential race in Florida, it can’t be discounted.

I think with Marco Rubio’s success, the voters in Florida won’t have much buyer’s remorse, and the Crist association won’t help Obama.