Former Republican presidential candidate Herman Cain formally endorsed Mitt Romney for president of the United States today, telling reporters that he was making the endorsement now "for unity" within conservative circles because "in order to win, we have got to rally around our nominee."

"This is about unity and, today, I want to formally endorse Gov. Mitt Romney for president of the United States of America," Cain said Wednesday afternoon on Capitol Hill. "It is clear that Gov. Mitt Romney's going to be the Republican nominee and so I wanted to formally endorse him today for president of the United States of America."

Cain said that, while many conservatives "may not be as excited" about the primary process or Romney's candidacy, the country is at a turning point and must elect a Republican.

"Gov. Romney gets it right on the big issues," he said. "President Obama gets it wrong on all of the big issues. That's why we have got to have a different occupant of the White House."

Asked why voters should listen to his latest endorsement after he initially signaled support for "the American people" and then Newt Gingrich, Cain attempted to poke fun at President Obama's evolution on gay marriage.

"My endorsement evolved," he said to laughter. "Early in the process is one thing, but as we converge toward the convention, what we did earlier isn't as relevant. It wasn't a matter of changing my mind."