Former Republican presidential candidate Newt Gingrich hits the campaign trail again Friday to support the presumed nominee, Mitt Romney, at the Georgia GOP convention.

The speaking engagement, however, was already on the books from when Gingrich was still a candidate. Gingrich is footing the bill for this trip, but he is expected to make a second appearance in Georgia  for Romney shortly after the state's convention, but the campaign would not specify details.

Gingrich spokesman R.C. Hammond told ABC News that Gingrich's goal was to help Romney win Georgia, as well as several other "key states."

Gingrich will also appear with Romney on the trail in Las Vegas later this month.

"I'm going to be with him at the end of the month in Las Vegas at a big event, and I'm going to do all I can to help Mitt," Gingrich said on the Laura Ingraham Show Friday.

But their togetherness comes at an uncomfortable time. As the attacks over Romney's involvement with Bain Capital spew forth  from the Obama campaign, many are reminded of the source of the original Bain attacks against Romney during the primary - Gingrich and his super PAC,  Winning Our Future.

Winning Our Future paid for a 28-minute documentary called "King of Bain: When Mitt Romney Came to Town," which called Romney a " predatory corporate raider." Gingrich got in on the Bain Capital rhetoric while campaigning in New Hampshire.

"I do draw a distinction between looting a company, leaving behind broken families and broken neighborhoods and leaving behind a factory that should be there," Gingrich said at a newsconference in January.

The attacks were criticized by conservatives, including Rush Limbaugh and Rudy Giuliani.

"What the hell are you doing, Newt?" Giuliani said on Fox News. "The stuff you're saying is one of the reasons we're in the trouble we're in right now."

Hammond told ABC News that many of Gingrich's criticisms on Bain Capital were mostly Gingrich asking for an explanation, and he said many in the Republican Party accept Romney's explanations. "Gov. Romney gave adequate explanations to the questions," Hammond said.

"I think it's a legitimate question about exactly what happened. Where did the money go? Who got the money? What happened to the people involved?" Gingrich said in January.

Past attacks aside, Hammond said Gingrich would still be effective on the stump for Romney, drawing a distinction between "Obama's failures" and Romney.

"Anything Obama is going to do is going to be far worse," Hammond said. "It's not about Newt Gingrich and Mitt Romney; it's about the failed leadership of Obama."