Former Florida Gov. Jeb Bush (R) today endorsed Rep. Connie Mack IV for Senate.

Mack has scored some big endorsements in his bid for the GOP Senate nomination, from Republican presidential nominee Mitt Romney to Sen. Rand Paul (R-Ky.). But Bush’s nod may be the most important of all.

“Connie Mack is the principled conservative that the people of Florida deserve representing them in the U.S. Senate,” Bush said in a statement released by the Mack campaign. “Connie has the courage, conservative values, experience and determination to confront the tough issues facing our nation. We must return conservatives to the majority in the U.S. Senate. Connie is the person Floridians need in Washington working with Senator Marco Rubio to reduce our national debt and limit out-of-control spending.”

Mack is the strong frontrunner in his primary race against former Sen. George LeMieux.

The GOP nominee will take on tw0-term Sen. Bill Nelson (D) in the fall. Roll Call rates the race as Leans Democratic.