TAMPA (AP) — 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.

The official wasn’t authorized to speak and requested anonymity.

Crist announced Sunday that he is endorsing Obama. Republicans called the decision political opportunism and pointed out Crist has previously criticized the president on issues like his health care overhaul.

Crist changed his voter registration to no party affiliation after he dropped out of the 2010 Republican Senate primary and ran as an independent. Many speculate that he will return to politics as a Democrat and possibly challenge his Republican successor, Rick Scott.