The golden-hued clips from his old home movies show Mitt Romney through the years: playing with his young children, sitting at the family table with Ann and the brood, holding hands with his bride on a beach.

"I think people understand that I'm a man of steadiness and constancy," Romney says in the TV ad, currently covering Iowa like a blanket of snow. He notes that he's been wedded to the same woman for 42 years, worked for the same company for a quarter-century, and, "I've been in the same church my entire life."

It does not take hermeneutics to tease out what he's trying to get across: I am not Newt Gingrich.

The former House speaker is on his third marriage, had to quit his leadership post because of ethics issues, and is a recent convert to Catholicism. Romney doesn't say those things explicitly, but he doesn't have to for the small, activist audience he needs: Republicans, many of them evangelical Christians, who will vote in Iowa's caucuses in 23 days.

In some ways, media consultant Russ Schriefer's 30-second ad encapsulates the story of the 2012 GOP race to date - the Gingrich surge, the latest twist in a race with so many changes they create cognitive whiplash, and the problem of Romney himself, which has kept his support at a ceiling of roughly a quarter of the Republican primary electorate: Conservatives mistrust the former Massachusetts governor for straddling the right and the middle in a party that no longer has a left. Some wonder whether he has any core beliefs.

Gingrich, the latest Anybody But Mitt, has surged out to a lead nationally and in the Iowa, South Carolina, and Florida polls. Romney is hanging on to a lead in New Hampshire, but the fear in his camp is that Gingrich could win those other early primaries and do well enough there to start a stampede.

Strategically, Romney had been counting on consolidating the center/establishment parts of the GOP and watching the right divide itself among several candidates. But the polls suggest that at least for now, Gingrich is the one doing the consolidating - coalescing the party's conservative strands around himself as the vehicle to stop Romney.

Along with the TV blitz, Romney's campaign has pushed out an online ad that labels Gingrich not conservative enough, based on his past criticism of U.S. Rep. Paul Ryan (R., Wis.) for proposing to replace Medicare with a subsidy program to help seniors buy private insurance. A pro-Romney "super-PAC" also has pledged to spend up to $3 million in Iowa over the next few weeks blasting Gingrich.

Well-financed as the latest TV barrage is, the cheaper, online part of Romney's blitz reflects one of the oddities of this campaign: a comparative paucity of traditional TV ads.

Why? For one thing, the GOP campaign has been defined by the near-weekly series of televised debates and the free publicity that accompanies them, and some candidates have made strategic decisions to hold their fire.

For another, Romney's not alone in going online. Campaign advertising has been migrating to the Web, with strategists placing video and other ads on sites frequented by voters in targeted demographics.

Online ads are nimble and more cost-effective than direct mail or TV, experts say. Campaigns are figuring out what corporations, which spend up to 28 percent of ad budgets online, already know. (By contrast, about five percent of campaign ad spending has gone to the Web.)

"Online advertising cuts through because of its ability to target. It's unparalleled in any medium," Zac Moffat, Romney's digital director, told the Associated Press recently. "TV may be more effective for driving a big message, but per usage, the Internet is more powerful."

But nimble or not, Romney's inevitability strategy - call it "Mitt Happens" - has been shown to have its limits. His advisers say they always anticipated the rise of Gingrich, or somebody, who would gather up the anti-Romney vote, and they are counting on their money and organization to weather a drawn-out nomination contest.

In that sense, it could echo President Obama's 2008 nomination run, which relied on superior organization in smaller states against Hillary Rodham Clinton's strategy of seeking a knockout blow in the big ones.

Or as Charles Kopp, the Center City lawyer who is state chairman of Romney's campaign, said: "It's entirely possible that the Pennsylvania primary on April 24 could matter."

 
Contact politics writer Thomas Fitzgerald at 215-854-2718, tfitzgerald@phillynews.com, or @tomfitzgerald on Twitter. Read his blog, "The Big Tent," at www.philly.com/BigTent.