ST. PETERSBURG, Fla. (AP) — Former Florida Gov. Charlie Crist, who was elected as the state's chief executive as a Republican and then ran for the U.S. Senate as an independent, announced on Twitter on Friday night that he's switching to the Democratic Party.

Crist sent out a Tweet that said, "Proud and honored to join the Democratic Party in the home of President (at)Barack Obama!"

The Tweet included a photo of a smiling Crist and an unidentified woman as he held up a Florida voter registration application. The Tampa Bay Times reports that Crist signed the papers changing his affiliation from independent to Democrat at a Christmas reception at The White House.

A message left for Crist wasn't immediately returned Friday night.

Crist was elected Florida governor in 2006 while in the GOP. As he moved to run for the U.S. Senate in 2010, he faced a tough primary challenge from the right and bolted the GOP to run as an independent. He lost a three-way Senate contest in 2010 to Republican Marco Rubio.

Crist spoke at the Democratic National Convention in Charlotte that nominated President Barack Obama for a second term. Crist, 56, is also viewed as a potential Democratic challenger to Republican Gov. Rick Scott in 2014.