Last night was a terrible night for Mitt Romney

Mitt Romney "won" the Iowa caucuses last night by 8 votes. Eight.

Over Rick Santorum, who is mostly broke, completely unable to self-finance a multi-million dollar campaign and who -- despite relentless retail politicking -- was polling in the single digits until last week.

The order of finish is irrelevant. Last night cannot be spun as a Romney "victory" in any reasonable way.

Romney has outspent and out-organized every other candidate by a considerable margin. As a 2008 contender, his name recognition is the most widespread of any of the seven contenders. He has been running for president for the last five years. To the extent a Republican "establishment" exists -- the Weekly Standard, the Wall Street Journal editorial board, Fox News contributors, former congressional surrogates and so forth -- it is firmly and unquestionably behind Romney. He enjoys every imaginable advantage.

And yet he won by eight votes?

Romney finished in second in the caucuses in 2008, taking 25% of the vote. Mike Huckabee won with about 36 percent.

In 2008, he faced a comparatively formidable field that included John McCain, Rudy Guiliani and Mike Huckabee. Any of these men would be considered frontrunners in the much weaker 2012 field. The 2012 field is, as Ross Douthat noted, the weakest field of contenders of either major party in a generation. And even with Jon Huntsman ignoring Iowa entirely and Michele Bachmann's support evaporating, Romney managed to secure less of the caucus vote this time around.

Romney should have blown this field out, taking at least a third of the caucus-goers. Instead, he performed worse than he did in 2008.

This demonstrates that the real winners of the Iowa caucuses were Santorum and Ron Paul, who both have been ignored by most media outlets and brushed aside by the "establishment" (again, to the extent one exists). The fact that either man was within a mile of Romney speaks to both their retail politicking skills, the degree to which their respective messages appeals to a strong, core group of followers, and how unhappy the majority of the party is with Romney.

In a normal political climate, Paul and Santorum shouldn't have come anywhere near Romney -- this is especially true if one tunes into talk radio or opens the Wall Street Journal.

This shows that Romney is an incredibly susceptible frontrunner, no matter how much cash he may have in the bank. I've said it many times: If he can't convince a conservative primary electorate to vote for him, I have a hard time seeing how he'll run competitively against an incumbent president who, despite declining approval ratings, voters generally seem to like personally.

The conventional wisdom is that Romney is the most "electable" Republican in the race, but the more voters see of him, the less they seem to care for him.

His support should be peeling away rapidly. It won't, but that's only because Republicans are content parroting the "electability" argument -- which falls apart when it's time to count the votes.