Mitt Romney may not look like a giant after an Iowa caucus win likely to go down as the tiniest victory in the annals of modern politics. But the former Massachusetts governor is poised to make history.

His expected victory in next Tuesday’s New Hampshire primary would make him the first Republican, other than an incumbent president, to win Iowa and New Hampshire back-to-back. That would be a huge achievement, propelling him forcefully into the rest of the primary season and quite possibly ending the Republican race well before the first big round of elections on Super Tuesday in early March.

Romney eight-vote margin in Iowa, over the lightly regarded Rick Santorum, inevitably diminishes his achievement. It reminds party activists, Republican voters and the average campaign watcher of Romney’s shortcomings as a candidate and makes him look like anything but an overwhelming front-runner for the GOP nomination. He remains stuck at a relatively modest level of support, highlighted by the anemic 25 percent of the vote that he received in the first test of 2012.

Easily forgotten,though, is how he got there, and why. The dominance of evangelical Christians made Iowa an unfavorable playing field for his more moderate brand of conservatism (not to mention his Mormon religion). To keep expectations low, Romney shrewdly gave Iowa little attention for most of last year, to the point that there were serious questions – and complaints from Republican Gov. Terry Branstad--about whether he was really competing there at all. He only went for the kill in the late stages of the campaign, less than two months before the vote.

An Iowa-New Hampshire sweep would make Romney almost a prohibitive favorite to become the party’s nominee. That, in large part, would be a result of his carefully planned and well-executed run for the presidency.

It also guarantees that the next six days will be among the nastiest of the entire Republican campaign, as his rivals pull out all the stops in an attempt to slow his progress. Rick Santorum’s stunning rise out of nowhere to gain a virtual tie for first place reflected the strengths of a candidacy that had been largely overlooked. He’ll gain attention—and tough scrutiny—in coming days.

But Romney’s success reflects the overall weakness of the Republican field. The challengers he now faces, as the primary season gets under way in earnest, will be hard pressed to stop him. The man with perhaps the best chance to give him a run for his money—Gov. Rick Perry—is back home in Texas, licking his wounds and, presumably, preparing to end his candidacy.

None of the remaining rivals has anything close to the financial resources of Romney’s campaign, an important factor as the race turns toward states where paid advertising plays an important part in shaping voter attitudes.

New Hampshire voters, notoriously contrarian, will no doubt find reasons to vote for one of his opponents. The 20-point poll lead that Romney built in the Granite State will likely diminish by the time all the votes are counted next Tuesday.

And that will lead to another round of questions about his breadth of support and commentary about the lack of enthusiasm, especially among conservatives, for his candidacy. But unless the unexpected happens—and as the Iowa caucuses demonstrated, nothing should be taken for granted in this volatile and weird campaign season—Romney will be on his way to an early victory in the nomination chase and a strong challenge in the fall against President Obama.