Crist wrote in the Tampa Bay Tribune Sunday that while the Republicans portray Obama's first term as a failure, the GOP has in fact "has failed to demonstrate the kind of leadership or seriousness voters deserve."
The former Republican governor said his party had veered too far to the right to effectively address important issues involving women, immigrants and senior citizens and called Obama "the right leader for our state and the nation."
Crist saw his own political career largely derailed in 2010 when he was bumped aside while running for the U.S. Senate by Marco Rubio, a rising star within the Tea Party movement.
The Wall Street Journal said Crist's loss was blamed by some observers as a consequence of his cordial relationship with Obama. Crist said he felt obligated to support the president as the United States grappled with the recession.
The Florida GOP responded to Crist's endorsement by calling it a "a repugnant display from a self-centered, career politician."