The straw poll is a storied event in Republican presidential politics, a mega fund-raiser-cum-horse race that tends to be a good predictor of who succeeds in the caucuses. Since the first straw poll in 1979, every candidate who has won the caucuses has performed well in Ames. Conversely, poor performances in the straw poll have ended campaigns. One 2008 Republican candidate, former Wisconsin governor Tommy Thompson, has said his campaign is effectively dead if he doesn't finish in the top two in Ames.

Romney is already seeing positive signs. In the Des Moines Register poll, he fared even better among likely straw poll participants, winning 34 percent to Giuliani's 16 percent and McCain's 15 percent.

But the best indicator might be his strong organization, which is essential for getting supporters to the Ames poll. Romney made a savvy move early in signing up Gentry Collins, a well-regarded former executive director of the state party. Collins, as Romney's state director, now leads a staff of 16 people. Romney also spent $77,000 in the first three months of 2007 for the services of Nicole Schlinger, a fund-raising and organizing specialist who is helping lead Romney's straw poll efforts.

"The man is organized, and the people are good," said Susan Frazer, a former Republican county chairwoman in Scott County, Iowa, who said she likes Romney but remains undecided.

One small window into the campaign's ground game came a few weeks ago, when Nick Lantinga, an influential GOP activist from northwest Iowa whom Romney has courted, stopped by a Thompson event at Family Table Restaurant in Sioux Center. Hours after he got home, Lantinga said, he received a phone call from a nearby city councilor who is also a volunteer for Romney's campaign.

"What are you doing there?" Lantinga, who is undecided, said he was asked.

Iowa, because it votes first in the primary season, wields outsized power in the presidential nominating process, often making or breaking campaigns for the White House. Though Iowa caucus-goers have had mixed success in selecting the eventual nominees, a win — or at least a strong showing — in the state delivers a major lift.

Romney's advisers are sanguine about his chances, but they are not taking anything for granted. And they know that being the front-runner invites a whole new set of unwelcome expectations.

Alex Gage, a Romney campaign strategist, used a recent memo to supporters to try to dampen expectations. "While we should feel good about coming so far so quickly, we should also not lose sight of the fact that our early lead in Iowa and New Hampshire today guarantees nothing." (Gage's memo was first reported by The Hotline.)