DES MOINES, Iowa — There is Rick Perry, a stained-glass window and a large illuminated cross over his right shoulder, looking more preacher than politician. An aerial shot of a soaring church steeple zooms into focus a few seconds later. Then — blink and you'll miss it — a picture of the Texas governor with his arm around Mike Huckabee flashes on the screen.

In more overt ways than ever, Republican candidates vying for support from Iowa caucus-goers are turning to religious language and imagery in their advertisements, seeking to appeal to the Christian conservative base that will play a pivotal role in determining the victor here.

Gone are the suggestive and purportedly subliminal images of campaigns past, as when Huckabee caused a stir in 2007 after releasing a commercial that appeared to show a cross floating in the background.

The new, more pointed religious references reflect how campaigns are scrambling for support among evangelicals who are still divided over whom to support as the caucuses near.

"At this point in the game, the candidates in the GOP primary don't have the time or the money for subtlety," said Mark McKinnon, a Republican media strategist. "They will light a fire and stand by a burning bush in order to send a signal to evangelicals, 'I'm one of you, vote for me.' "

Perry has released four commercials in which Christianity is a theme.

"We grew up in small towns, raised with Christian values," his wife, Anita Perry, says in one spot running in Iowa now. "And we know Washington, D.C., could use some of that."

A former patient of Ron Paul, who practiced as an obstetrician before going into politics, says in one commercial, "It's not hard for someone who is a Christian and who truly believes to stay on the right path, and I think that's the kind of person Ron Paul is."

And an ad in which Newt Gingrich and his wife, Callista, offer their Christmas greetings pivots first to a sketch of a nativity scene and then to a church.

Politicians have long employed coded language in their messaging to religious conservatives, a practice often derided as dog-whistle politics for its ability to stir emotions among those who are in-the-know while passing undetected over others. Sarah Palin has often referred to her support from "prayer warriors," a term known among evangelicals as those who engage in battle with Satan.

The 2004 Bush-Cheney campaign used billboards with faint images of crosses. And at the Republican National Convention that year, the lecterns on stage were made of two-tone wood that appeared designed to resemble crosses. The Bush campaign insisted it was a coincidence. Where some people see a rusty water stain, after all, others see the Virgin Mary.

But what is different this year, media strategists and analysts said, is the extent to which the candidates are distributing such unambiguously religious messages so widely.

"Have those messages been used in previous elections? Certainly," said Kenneth M. Goldstein, president of Kantar Media's Campaign Media Analysis Group. "But they would end up in a mail piece, a phone call, a talk show radio ad. Now we're seeing a much broader, shotgun approach on broadcast television."

Some campaigns are going to great lengths to develop and hone these ads. The commercial with Anita Perry features a shot of the red brick church in which she married her husband in Haskell, Texas, underscoring the governor's commitment to traditional marriage.

And the ad Rick Perry has received the most criticism for this election, in which he says "there's something wrong in this country when gays can serve openly in the military but our kids can't openly celebrate Christmas or pray in school," was specifically written and staged by the governor's media team to appeal to Christians who feel the Obama administration is hostile to public expressions of faith. The scene, a verdant, bucolic hillside, was meant to invoke a meditative setting suitable for prayer.

The ad with the church steeple and the split-second shot of Huckabee (who said Tuesday that he was unaware his image was being used) aired only over the holidays and in select Iowa markets. The Perry campaign bought time during programs it knew would appeal to the audience it is trying to reach, like football and "The Sound of Music," what Ray Sullivan, Perry's communications director, called "family friendly TV."

Not all candidates have been so overt. Mitt Romney, whose Mormon faith is viewed by many evangelicals as heretical, has only opaquely referred to being a lifelong member of his church in his advertisements. Rick Santorum has opted to highlight in his newest commercial other aspects of his biography that resonate with evangelicals, like his authorship of legislation that was intended to curb late-term abortions and the fact that his children have all been home-schooled.

Such unabashed appeals to evangelical Christians underline not only how intense the battle is for their support but how fractured and unsettled that part of the electorate remains less than a week before the caucuses.

"In 2008 there wasn't another candidate who was explicitly targeting the Christian evangelical vote," said Arthur Sanders, an associate provost at Drake University who studies media and the electoral process.

"Whereas this time you have Perry, Santorum," Michele Bachmann and, "to a lesser extent Gingrich. And I think that increases the baldness with which they're willing to target that audience."