Updated

"We're going to win this thing with all of our passion and strength and do everything we can to get this campaign on the right track to go across the nation and to pick up other states and to get the ballots I need and the votes I need to become our nominee."

-- Mitt Romney campaigning in Marion, Iowa.

Mitt Romney may win the Iowa Republican caucuses today, and he may do it without improving his showing of four years ago.

The media narrative will probably be all about former Pennsylvania Sen. Rick Santorum or Texas Rep. Ron Paul. Whichever of them does best, especially if they edge out Romney, will receive a tremendous boost in exposure while the pundits pontificate on the question of what it means for a libertarian or a die-hard social conservative to win.

There will be enough hot air emitted on the subject to melt the butter cow sculpture at the state fair, all gassing on about the significance of Paul's ground game or Santorum's ceaseless pleading.

A difference of a few thousand votes in a state of 3 million is not exactly a Reagan-sized landslide, but political journalists won't be able to resist over-interpreting. It's kind of what we do.

But that will be missing the story, which, whatever the order of the top three finishers, is really about Romney.

In 2008, Romney spent millions of dollars and countless hours campaigning in Iowa and took in 25 percent of the vote, nearly 10 points behind winner Mike Huckabee. This time around, Romney initially shunned the state – refusing to enter the summer straw poll in Ames and mostly declining to campaign here.

The state, a bastion of social conservatism and anti-establishment orneriness, had been deemed unwinnable for the moderate, establishment-backed Romney and was accordingly written off by his campaign.

And after all that, what was Romney's share of the vote in the final Des Moines Register poll? Twenty-four percent.

Yes, there was some residual goodwill and some organization left over from Romney's 2008 Hawkeye blitz, but for all the talk about how Iowa is so different from the rest of the country, Romney's showing in polls here is nearly identical to his national standing.

He's got a quarter of the vote in Iowa, just like he does in the rest of the nation. Iowa Republicans are rightly nervous that if Romney wins, this comparability will encourage future top-tier candidates to spend less time nuzzling Hawkeye voters and opt for national campaigns, but what counts for Republicans in the other 49 states is this: Romney's quarter may be enough to win him the nomination.

Consider this, if Romney got the same percentage of the vote as he did in 2008 in Iowa (25 percent), New Hampshire (31 percent), South Carolina (15 percent) and Florida (31 percent), he would very probably rack up three wins and a second or third place finish this month. That would be more than enough to seal his status as the unstoppable frontrunner and cause restive conservatives to give up on their goal of defeating him.

One certainly wouldn't expect Romney to do worse than he did in 2008, and polls suggest that he might improve his showing in the three upcoming primaries, particularly in South Carolina.

We know Paul and his supporters aren't going anywhere, and will likely draw just under a fifth of delegates in early contests. Given his Iowa surge, Santorum will be encouraged to try to do the same thing in the January primaries and might end up garnering more than a tenth of the vote this month. And even if Michele Bachmann lacks a path to victory, she may be motivated to keep pushing her message as long as anyone is still listening and could soak up a point or two.

There remains a danger for Romney that after today's caucuses, either Newt Gingrich or Rick Perry will start to unite the right. But so far, while three quarters of the GOP electorate may agree that they prefer someone other than Romney, they remain hopelessly divided as to whom that should be.

That's why the second most important story of the day will be who wins in the battle between Perry and Gingrich. If Gingrich craters tonight or Perry can't get into the top tier there would be a strong argument in either case for the loser to bow out or at least for supporters to move on to a more viable candidate.

But as it stands today, Romney's cruise control candidacy looks like a winner.