Is Mitt Romney losing the evangelicals?

Top Line

In a close election, like the one Barack Obama and Mitt Romney appear to be locked in, the winner is often decided by turn out. That is, when the party faithful are enthusiastic and energized , they come out to vote in large numbers. But if they're not excited, or angry, or otherwise energetic, they stay home. And the other guy, or gal, wins the election.

This year, Mitt Romney is trying to fire up two major groups of Republican voters who have been instrumental in recent elections: evangelical Christians and members of the Tea Party movement. And frequently, these people are one and the same, hence the term coined by journalist David Brody: 'Teavangelicals.'

In his new book, Teavangelicals: The Inside Story of how the Tea Party and Evangelicals Are Taking Back America, Brody, the chief political correspondent for the Christian Broadcasting Network, explores the political heft these combined populations are having on today's political scene.

But Romney is neither a Tea Partier, nor an evangelical. And while he can count on the support in the general election from many of the voters that supported Teavangelical candidates in the Republican primary — after all, they aren't likely to support President Obama instead — will they have enough enthusiasm to drive high voter turn-out? Brody says that remains to be seen.

"The folks that were actually voting for Herman Cain and Bachmann and Santorum, they'll show up and vote for Romney even if they have to hold their nose, that's not the issue. The question is, are they going to bring a friend? And are they going to mobilize? It's all about voter turnout," Brody says.

Romney's upcoming selection of a running mate has the potential to secure the support of the Teavangelicals, or turn them off in a way that may be irreparable, Brody warns. Who would be a pick that would anger the Teavengelicals? New Jersey governor Chris Christie, for one. Who would they approve of as a veep pick? Brody says put former Minnesota Governor Tim Pawlenty, Florida Senator Marco Rubio and even Louisiana Governor Bobby Jindal on that list.

Teavengelicals would love to see former Arkansas Governor and talk show host Mike Huckabee get the Romney nod, but that's not likely to happen, Brody agrees. Romney needs the Teavengelical vote, but he won't pander to it quite that much.

How else can Romney capture the Teavangelical support? He can stop talking about the economy, economy, economy, Brody suggests, and turn to a little-disussed topic, his faith.

While the Romney campaign has been downplaying his Mormon faith this campaign, perhaps for fear it could turn evangelicals further away, Brody thinks a candid speech about faith could be just the thing Romney needs. But Brody suspects, Romney won't do it.

"He really is missing an opportunity. He doesn't want to go there with his Mormon faith, and yet, if he wants to connect with folks on that personal level, he can point to his time as bishop in his church where he talked about - he actually counseled people out of abortions and a lot of things that evangelicals would be very interested in, he just won't go there," Brody says. "He doesn't need to show up at a pro-life rally, necessarily, but he does need to incorporate more of this on the stump."

ABC''s Arlette Saenz and Sarah Burke contributed to this report.