Well done, and almost certainly too late to do him any good. Although how much good would it have done him, really, if he’d started airing it a month ago? Offhand I can’t think of a single positive ad that’s changed the game for any candidate. The gamechanging moments in the campaign have all come at the debates or after an onslaught of negative ads. Which reminds me: If Romney ends up winning tonight and sweeps through New Hampshire, South Carolina, and Florida this month, here’s a fun fact out of Iowa that’ll haunt you forever.

Mitt Romney has long been considered the frontrunner for the 2012 Republican presidential nomination, but if he wins Iowa’s caucuses on Tuesday, it will be partly because of one extraordinary fact: Not one of his Republican rivals ran a negative TV ad against him in the state.

Sure, Romney was sometimes mentioned in the onslaught of attack ads that swept Iowa airwaves in the final days of the campaign. Ron Paul ran a television ad trashing Romney and Newt Gingrich as members of the status quo who won’t bring the leadership necessary to really change Washington. And Make Us Great Again, a super PAC backing Rick Perry’s candidacy, ran ads that took aim at Romney and Gingrich, questioning their conservative credentials.

But none of Romney’s 2012 rivals ran an ad solely taking on the former Massachusetts governor—a sign that they perhaps underestimated his rise in Iowa.

That will all change dramatically in New Hampshire, of course, but by then it might be too late to stop Mittmentum. Go look at this chart of how much each candidate spent in Iowa. Contrary to popular belief, it wasn’t the rich guy who buried the state in advertising dollars. It was … Rick Perry. And somehow, unbelievably, neither he nor Ron Paul nor Gingrich ever got around to taking a shot at the one person in the field poised to wipe them all out before Super Tuesday. Says Byron York, “If voters are looking for the best alternative to Romney, they probably want to identify the candidate who can make the best case against Romney. Yet the potential anti-Romneys spent their time attacking each other. In the end, they didn’t help themselves and they let Romney off scot-free.” Try to find some comfort in this if/when a Romney victory tonight seals our fate: Unlike the rest of the field, Romney and his team at least could beat a bunch of five-year-olds in a strategic battle of wits.