Jae C. Hong, File, Associated Press
In this Feb. 22, 2012 file photo, Republican presidential candidate, former Pennsylvania Sen. Rick Santorum, left, and former Massachusetts Gov. Mitt Romney talk following a Republican presidential debate in Mesa, Ariz.
I don't think Romney has to worry about the Mormon vote. I don't think he'll be concerned about offending that constituency. —Matthew Wilson, Southern Methodist University professor

Related: The 2012 Veepstakes: 20 possible VP picks for Mitt Romney

SALT LAKE CITY — Now that Mitt Romney is running as the GOP presidential nominee, talk is turning to his pick for the No. 2 spot on the ticket.

"It's still way early," said Rep. Jason Chaffetz, R-Utah, who has campaigned for Romney around the country. "There are a number of good choices."

He, though, has already identified what he calls a great choice — fellow GOP Rep. Paul Ryan of Wisconsin, the author of the federal budget-slashing Ryan Plan already endorsed by Romney and many others in the party.

"The 'veepstakes' is a big one. You've got to get that right," Chaffetz said. "I'm a huge fan of Paul Ryan. You get somebody of that caliber, it'll help unite Republicans over the summer."

Ryan is on most of the pundit lists already circulating, along with Florida Sen. Marco Rubio, New Jersey Gov. Chris Christie, Ohio Sen. Rob Portman and Virginia Gov. Bob McDonnell.

Rubio, a Cuban-American, appears to be the current frontrunner. But there have been questions about Rubio spending several years of his youth as a Mormon before returning to the Catholic Church.

Choosing Rubio as a running mate likely would focus new attention on Romney's membership in the LDS Church, especially among conservative evangelicals who don't consider Mormons to be Christians.

"Romney's goal is to downplay discussions of his faith," particularly the "distinctness or out-of-the mainstream aspect," said Matthew Wilson, a professor specializing in politics and religion at Southern Methodist University in Texas.

Wilson didn't rule Rubio out as Romney's eventual choice, but did dismiss the chances of another current member of The Church of Jesus Christ of Latter-day Saints being his running mate.

"We didn't see John Kennedy chose another Catholic," he said, referring to the late president's own struggles to be accepted by voters uncomfortable with his faith a half-century ago.

Two former Utah governors, Jon Huntsman Jr., who dropped out of the presidential race early on, and Mike Leavitt, who served in President George W. Bush's cabinet, have been mentioned as potential contenders for the VP slot. Both are Mormons, although Huntsman has described his faith as "tough to define."

Huntsman endorsed Romney after ending his bid for the White House, but appears to be cutting ties. He has suggested a third-party candidate should emerge and his daughter has announced he won't campaign for Romney.

Leavitt has stayed close to Romney as a key adviser on the campaign trail and is described by Politico as often filing the role of the candidate's "first friend," and someone "who never tells him anything remotely challenging."

University of Iowa political science professor Tim Hagle said Romney faces trouble if he doesn't come up with a vice-presidential choice who bolsters his standing with conservatives.

"That's going to be a big decision on his part," Hagle said, noting an announcement could be expected in mid- to late-summer, in advance of the Republican National Convention in August.

The decision by Rick Santorum earlier this week to suspend his campaign for the GOP nomination gives  Romney more flexibility in the timing of that announcement, Hagle said.

Still, with former U.S. House speaker Newt Gingrich and Texas Rep. Ron Paul still in the race, Hagle said Romney "can't be too quick to do that. He doesn't want to seem too presumptive."

Dave Woodard, a political science professor at Clemson University in South Carolina, also said a VP candidate who can win over the GOP's conservative base is Romney's only real option.

But Woodard said that's not likely to be Santorum, who waged a tough primary battle against Romney. "When Rick Santorum walks into the room, he is the defeated presidential nominee," he said.

Wilson said Romney should consider the conservative candidate who gave him the hardest fight in the 2008 presidential race — Mike Huckabee.

"Huckabee obviously has strengths within the party where Romney has struggled, southern religious conservatives," the Texas professor said. "Huckabee makes a lot of sense in some ways."

The former Arkansas governor not only "locks down the conservative base," he also appeals to conservative women, who make up a significant portion of Huckabee's television audience on FOX News, Wilson said.

Utahns remember Huckabee for his comments about Romney's Mormonism during the last campaign. Many were upset when Huckabee, a Southern Baptist minister, asked, "Don't Mormons believe Jesus and the devil are brothers" in an interview.

Wilson said any discomfort Utahns might have with Huckabee on the ticket shouldn't be a factor in Romney's decision.

"I don't think Romney has to worry about the Mormon vote," he said. "I don't think he'll be concerned about offending that constituency."

Related: The 2012 Veepstakes: 20 possible VP picks for Mitt Romney

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