JACKSONVILLE, Fla. -

Former presidential candidate Newt Gingrich stopped by Mitt Romney's headquarters in Jacksonville on Thursday.

Gingrich spoke to volunteers at the location off Beach Boulevard near the Hart Expressway. The event was not open to the public.

"Jacksonville is extraordinarily important because you have to build up a substantial Republican majority here in order to carry the state, and I think we have every chance to do that," Gingrich said. "George W. Bush carried it by a big margin. I think that faced with what Obama's going to do to the Navy here, faced with what he's doing to hurt veterans, faced with what he's done in jobs, I think that there's a very real chance that Romney can carry it by a big margin, and that has a big impact on the Senate race."

The former House Speaker dropped out of the 2012 presidential race in early May. He vowed to help Romney's bid to defeat President Obama.

"This is not a choice between Mitt Romney and Ronald Reagan. This is a choice between Mitt Romney and the most radical, leftist president in American history," Gingrich said.

Gingrich bowed out of the race with more than $4 million in debt. As he was mulling an exit from the race, his aides were talking with Romney's campaign about how his one-time rival could help him retire the debt. Romney's team has offered to be helpful in that effort.