Des Moines - Mike Huckabee had been scheduled to speak this morning at the 11 AM service at the big Cornerstone Family Church on the south side of Des Moines, an event on the calendar that provoked breathless excitement among journalists here: The holy candidate, in the pulpit, on the last Sabbath before his great trial! But the holy candidate got a last-minute case of the willies and canceled the appearance, telling everybody he didn't want to make a big scene and would instead worship in an "undisclosed location." The undisclosed location turned out to be ... the Cornerstone Family Church. Sneaky sneaky!

Driving to Cornerstone from downtown, you enter real church country. Churches of every size dot most big intersections; the Wakonda Church, the Rock of God, St. John's (whose marquee reads: "GOD LOVES YOU AND HE APPROVES THIS MESSAGE"). There's a ton of places Huckabee could've slipped off to if he had really wanted to pray in peace. But, of course, he didn't -- he just wanted the press to think he wanted to. Cornerstone is too perfect a representation of what he wants his campaign to be for him to pass it up. It's fast-growing. It's rock-and-roll, with a band and a heavily-amplified gospel choir. It's diverse -- the morning congregation looked about half white and half black. And it's very morally fervent. "It is my desire that the institution of Marriage not to be redefined [sic] and that the statement below be added to my parties platform," reads a little sheet of paper church wardens pass out during the service, with the instruction to bring it to our caucus locations on Thursday. Even its name is eerily apropos. Isn't Huckabee the stone the builders of the GOP race rejected

After a lot of singing, Pastor Dan Berry launches into his sermon, which is about the power of momentum. "In your life, there's going to be a lot of opposition that comes up in the way of your dream. Like Jesus, you will have to plow through a lot of hostility," he explains, suited up in a fashionable black mock turtleneck and tan blazer for the occasion. Berry's got plenty of statistics ("90% of failures come from people who quit too soon") and aphorisms ("an oak tree is nothing more than a little nut who held its ground") to buttress his argument. But the most powerful moment, the crux of the sermon, is a story he tells about a time he watched a Strongman competition on TV. Berry is a real ham, and, as the church crowd hoots with laughter, he moves away from the podium and rubs his thighs and flexes his shoulders and grunts like the bodybuilder he was supposedly watching, who had been harnessed up to a commuter bus. As the bodybuilder leaned forward -- Berry leans and groans to demonstrate -- Berry suddenly wondered what would happen if somebody stuck a little piece of wood under the bus's wheels. Before the bus got moving, he suspected, a little piece of wood like that would have been too much for for the bodybuilder to get it started over. But then the straining bodybuilder began to take steps. "He got moving," Pastor Berry says. "The bus started really rolling. And now he's moving! And I thought, if you had put a block under the bus's wheels, it would have just gone ploomp-ploomp, right over it!" 

The story feels like a passionate open letter to Mike Huckabee. You have momentum. Just keep pulling the direction you've been pulling, and you'll just go ploomp-ploomp right over all the attacks Romney and the others throw under your wheels. If Huckabee had been in the audience, the Strongman story -- so clearly a tribute to him -- could have been a tremendously powerful moment. But he wasn't. He had ducked out earlier, before I arrived. "He busted right out the back as soon as I said the word 'caucus'!" Berry says after the service. 

The truth is, Huckabee's gotten to the edge, and he's blinking. Unlike the eleven other candidates criss-crossing the state, he is taking the entire day off campaigning, reportedly to rest and prepare for a marathon, and I don't think the "marathon" is figurative. Dealing on the trail yesterday with the increasingly intense attacks against him, he seemed off his game, even nervous. He decided to do a church service, but then he did it halfheartedly, which is probably worse than not showing up at all. Sneaking out under everybody's noses provokes the vague feelings of resentment that Hollywood stars do when they refuse to give their poor fans autographs. 

If Huckabee's really starting to feel nervous that talk of religion and talk of the caucuses are getting too mixed, then his candidacy is doomed, since it's built on that mixture. Getting up after the service, I start to think canceling the original glitzy Cornerstone appearance was a big mistake. Opportunistic, showy, yeah, it probably would have been all of that. But I actually suspect Republicans in Iowa haven't hit their saturation point on that kind of thing, and Huckabee has room to take it further over the top. A destiny argument is what's brought him this far. It's the source of his incredible momentum, as Pastor Berry suggested. 

Not every campaign feels ashamed to be working the churches the Sunday before the caucuses. Stationed near the door at the end of the Cornerstone service is Obama volunteer Arrington Dixon, a former D.C. city councilman with a benevolent smile who's come to Iowa all the way from the Washington neighborhood of Anacostia. Unwilling to entirely cede the legions of the faithful to Huckabee, the campaign dispatched Dixon here.

A parishioner I sat next to during Pastor Berry's service explained to me that, in theory, he didn't really like his politics mixing with his church life. You hear that idea a lot around here. But he conceded that this feeling is abstract, more of an intellectual or constitutional point than a strong emotion. And instead of spurning Dixon on their way out of the church, a number of people, both white and black, stop to take pamphlets and "People of Faith for Obama" stickers from him as they leave. Nobody I ask says they're annoyed Dixon is here -- one young woman in red actually mentioned happily that she saw him sitting through the whole service wearing his Obama button and even singing along with the hymns. A little shamelessness can go a long way.

--Eve Fairbanks