Former Governor Mike Huckabee will endorse Marco Rubio over Governor Charlie Crist for the U.S. Senate seat from the state of Florida, CNN reports. Incumbent Senator Mel Martinez (R-FL) will not seek re-election in 2010, having served just one term.

The endorsement could be quite a catch for Rubio, the conservative former Speaker of the Florida House of Representatives. Huckabee is quite popular with religious conservatives and his blessing (if you’ll pardon the pun) could bring volunteers and cash to the underdog campaign.

It’s also a bit of a loss for Governor Crist, who’s still reeling amongst the conservative base over his support for porkulus and other big government measures. While the one-term governor holds a significant lead in early polls, the same surveys indicate that Rubio suffers from a lack of name recognition. Many months of campaigning could close the gap significantly in the usually-red Florida.

If you’d like to help a true conservative get elected to the U.S. Senate, here’s Rubio’s website.