Charlie Crist's political transformation is now complete.
The former Republican governor of Florida became an independent in 2010, then at a Friday night party at the White House, officially signed papers to become a member of the Democratic party.
POLITICO reports Crist signed the papers at a holiday reception at the White House and tweeted the official announcement.
"Proud and honored to join the Democratic Party in the home of President," Crist wrote.
"I've had friends for years tell me, 'You know Charlie, you're a Democrat and you don't know it,'" Crist told the Tampa Bay Times about his party switch.
Crist, whom the Times said referred to himself as a "Ronald Reagan Republican" and a "Jeb Bush Republican", has been trending Democratic since he lost a GOP Senate nomination to Marco Rubio.
According to the Huffington Post, Crist switched his party affiliation to independent in order to run against now-Senator Rubio in the general election. He ended up losing to Rubio by 19 points.
He moved further to the left and in October, endorsed Obama for reelection and delivered a speech at Obama's 2012 nominating convention in Charlotte, N.C. this September.
"I didn't leave the Republican party," Crist said in his speech. "It left me."
The newly minted Democrat is widely expected to make another run for governor of Florida but is certain to face a tough primary challenge from those on the left who were not happy with his term as a Republican in the governors mansion.
Crist, 56, will likely challenge the unpopular current governor, Republican Rick Scott. Scott's approval rating has only been above 39 percent twice since he took office, according to Bloomberg.