Al Cardenas, a prominent Florida Republican fundraiser, political ally of the Bush brothers and chairman of the American Conservative Union, has endorsed Mitt Romney in the GOP presidential primary, the Romney campaign has announced.

The Romney campaign, which has long sought to woo conservatives in the party, emphasized Cardenas’ conservative credentials in making the announcement, quoting Romney as saying, ““Al has been a force in the conservative movement for many years. There are few people I know that share a deeper belief in the principles of smaller government and American exceptionalism than him.” It also emphasized his history as son of a family of Cuban exiles.

Cardenas became well-known in Florida politics when former Gov. Jeb Bush chose him to be state Republican Party chairman shortly after Bush’s election to the governor’s office in 1998.

Bush announced his own endorsement of Romney last week.

Cardenas previously had stayed neutral in the primary, saying his position as head of the ACU, an influential organ on the Republican right, required him to remain impartial. His move is another sign that leading Republicans are moving to line up behind Romney.