WASHINGTON – Newt Gingrich makes his first major appearance since leaving the presidential race this weekend and will try to boost Mitt Romney to a group that preferred Gingrich as the party’s nominee: Georgia Republicans.

And Gingrich -- who spent months on the campaign trail bashing Romney as insufficiently conservative, among other things – will bring a simple message to the state GOP convention in Columbus: “We have an absolute obligation to defeat Obama.”

In an interview Thursday, Gingrich said that despite their differences, Romney will be “dramatically more conservative than" President Barack Obama and thus deserving of hearty Republican support.

Gingrich dropped out of the presidential race this month and made only vague reference to the party’s all-but-certain nominee in his farewell speech. But he is hitting the trail on behalf of Romney and other Republicans. He is speaking at a fundraising dinner Friday night and to the full state convention Saturday in Columbus.

Gingrich said there are plans for the two of them to appear together in Las Vegas at the end of the month. In June Gingrich said he will be raising money in Atlanta for Romney and U.S. House Speaker John Boehner, with a Gingrich-Romney tandem appearance set for June 11.

The embrace of Romney puts Gingrich in an awkward spot, said University of Georgia political science professor Charles Bullock. If he were to start gushing about his former primary foe, it would look insincere.

“I expect Gingrich is also concerned about his own credibility,” Bullock said. “There’s only so much you can recant.”

Gingrich did not exactly recant, but did acknowledge the ineffectiveness of one attack he used on Romney – the private equity firm Bain Capital. When Gingrich accused Romney and Bain of taking over companies and downsizing them at the expense of workers, he was widely condemned by fellow Republicans and eventually backed off.

This week the Obama campaign released an ad along those same lines. Gingrich said his experience should be a lesson to Obama: “that dog won’t hunt.”

Gingrich said the attack will not resonate in voters’ minds as they think: “You want me to be mad because in one company somewhere Romney may have in fact been involved in someone losing their job while you as president have been involved in millions of people losing their jobs?”

A test for the Romney campaign will be to not only get votes from Republicans’ activist core but also their energy and money.

Bullock said Gingrich could help in that regard as, “It’s easier to swallow [Romney as the nominee] to see that one of the individuals they may have preferred is on board.”

Gingrich argues that Obama does the job himself, in part by supporting gay marriage.

“The president made Romney’s job of mobilizing his base much easier,” he said.

The former U.S. House Speaker took a little bit of time off after dropping out of the race, but he and his wife, Callista, are working on media projects for Gingrich Productions, the one piece of his former business empire still humming after his yearlong presidential campaign. Gingrich said he does not plan to revive the other parts of Newt Inc. – which included a think tank and consulting business – as “there will be more than enough to keep us busy” with Gingrich Productions.

He just put out an e-book focused on domestic energy production and his campaign pledge for $2.50 per gallon gasoline, and he said he is working on a novel about George Washington and the Battle of Yorktown due out in November. Callista Gingrich, meanwhile, is working on a sequel to her bestselling children’s book starring Ellis the Elephant.