By tapping this out even before Republicans begin their presidential debate in Boulder on Wednesday, I've crawled out on a limb. But the bough seems pretty solid, so I'll continue.

Donald Trump’s hold on the GOP nomination process is coming to an end. He’s lost his lead in Iowa, and is unlikely to get it back. Maybe he still wins New Hampshire.

But South Carolina, Georgia and the rest of the South are likely to desert the Manhattan billionaire in the end. It’s not the hair. It’s not the brashness. It’s not the shoot-from-the-hip style.

Trump has a deficiency that has always existed, but is just now coming into focus. He is not fluent in religion. In particular, Trump doesn’t speak Red State religion.

The weakness crystalized over the weekend, before a Florida crowd. Maybe you’ve seen the video.

“I love Iowa. And, look, I don’t have to say it, I’m Presbyterian,” Trump said. “Boy, that’s down the middle of the road, folks, in all fairness. I mean, Seventh-day Adventist, I don’t know about. I just don’t know about.”

The crack was aimed at Ben Carson, the retired neurosurgeon who now leads in Iowa – and in one national poll offered up this week by CBS and the New York Times. Carson is a Seventh-day Adventist, a Protestant denomination that celebrates the Sabbath on Saturday.

But in fact, the jab told religious conservatives far more about Trump. The billionaire has previously said his membership is lodged with the First Presbyterian Church in Jamaica, N.Y. Which is associated with the Presbyterian Church (USA). Which is a denomination with distinctive liberal leanings on issues such as immigration reform and gay marriage.

Conservative evangelicals are aware of this. Trump, apparently, is not. Or at least, not aware enough.

Then there was that famous July interview in which Trump derided U.S. Sen. John McCain’s status as a war hero. The billionaire spoke about religion then, too – but in a somewhat stale fashion. He cited the Rev. Norman Vincent Peale as an inspiration. Peale died 22 years ago, and left his pulpit in 1984.

Trump was asked if he’d ever asked God for forgiveness. “I don’t bring God into that picture,” he replied.

Last week, a poll conducted by the Des Moines Register and Bloomberg Politics showed Ben Carson surging past The Donald in Iowa. That same survey asked likely GOP caucus goers this question: “Do you think Donald Trump is or is not a committed Christian?” Thirty-two percent said yes, 28 percent said no, and 40 percent weren’t sure.

(Sixty-nine percent of those same Iowa GOP voters said it would be “unacceptable” to have a U.S. president who is Muslim, lining up behind Carson on that particular issue.)

One reason that CBS/New York Times poll gave Carson his first national lead: When it came to conservative evangelical support, Carson had a 20-point advantage over Trump.

Larger religious guns have begun to lock their sights onto Trump, including Russell Moore, the top public policy advocate for the Southern Baptist Convention.

“Most illogical is his support from evangelicals and other social conservatives. To back Mr. Trump, these voters must repudiate everything they believe,” Moore wrote in a New York Times op-ed piece, published last week. “We should not demand to see the long-form certificate for Mr. Trump’s second birth. We should, though, ask about his personal character and fitness for office. His personal morality is clear, not because of tabloid exposés but because of his own boasts. His attitude toward women is that of a Bronze Age warlord.”

Questioning from conservative evangelicals is likely to intensify as the GOP contest moves South. “I do public policy briefings all over the state,” said Mike Griffin, lobbyist for the Georgia Baptist Convention. “What I tell people today is to not look for conservatives. Look for candidates who represent a biblical worldview.

“I think that’s more important than candidates who call themselves conservative,” Griffin said. “The word ‘conservative’ can change a little bit.”

We have mentioned in past columns that Georgia’s March 1 presidential primary, particularly the GOP side, is likely to have an impact on debate over “religious liberty” bills before the state Legislature.

But another topic will be hanging over the Capitol in Atlanta: Casinos and gambling. And one source of Trump’s fortune.

Down in south Georgia, Kay Godwin is one of the most influential GOP activists on the ground. She hates casinos. “We need good jobs that are stable jobs, not encouraging people to waste money,” she said.

Godwin is also director of grassroots activity for Ted Cruz’ presidential campaign – and is very sure of the Texas senator’s religious credentials. “I think Ted has proven himself over the years. He’s argued in the Supreme Court on religious liberty issues and Second Amendment issues, and won all nine times,” Godwin said.

While Cruz is vacuuming up much of the religious conservative vote in Georgia, the Trump campaign is spinning its wheels.

The campaign acknowledged that it has let go Seth Weathers, a local Republican strategist tapped this summer to organize the Georgia campaign. “We have been in contact with our state leaders in Georgia and will announce a new state director in the near future,” Trump spokeswoman Hope Hicks wrote in an email.

“Mr. Trump is fully committed to winning Georgia and has begun allocating the resources necessary to do so,” Hicks wrote. “He received a warm welcome of an estimated 7,500 crowd during his first visit to the fifth largest delegate rich state in October and pledged to return soon.”