Ron Fournier of National Journal says something that hadn't occurred to me about Iowa and what comes next.
If Romney wins New Hampshire, he would be the first non-incumbent Republican to sweep Iowa and the Granite State since the modern caucuses were formed. There is a reason why that's never been done: Republican coalitions in Iowa and New Hampshire are mirror images of one another and, taken together, reflect the broad GOP electorate. In other words, a candidate who can win older, more conservative GOP voters in Iowa as well as white-collar, independent-minded Republicans in New Hampshire should be able to win everywhere.
Stop Romney in South Carolina? Well, he has essentially already won over a GOP coalition that resembles South Carolina's diverse electorate: Iowa plus New Hampshire equals South Carolina.
Of course, if conservatives had put a single candidate up against Romney, he wouldn't have won Iowa. But he did win, and in a state he fought for much less diligently than Santorum.
Sean Trende at RCP neatly sums things up. One, it was a good night for Romney. Two, the win does not make his nomination inevitable. Three, not this time maybe but one day, Rick Santorum's style of politics could capture the GOP.
Twice in a row now, the party has toyed with nominating a candidate who combined social conservatism with economic populism; Santorum's speech last night was essentially a northern version of a speech Mike Huckabee could have delivered in 2008.
We've already seen white working-class voters move toward the Republican Party over the past several decades -- a shift perhaps epitomized by the GOP's special election victory in New York's 9th Congressional District. If a more credible Santorum/Huckabee candidate could emerge, the party would reciprocate by moving toward these voters. This would have major implications for our political dynamic, and could deal the Democrats a serious blow in states like Pennsylvania and Ohio.
On the other hand, the Democrats have been moving toward a top-bottom coalition of "New Economy" professionals and minority voters. A Santorum/Huckabee-esque Republican Party would probably hasten the exit of upscale suburbanites from the Republican coalition, and potentially reinvigorate the New Democrat approach to governing that dominated the party's politics in the '90s.