Rick Santorum rose from the near dead to win all three Republican voting contests last night, halting Mitt Romney's momentum and throwing another huge curveball at the GOP. The Wall Street Journal called it a "stunner," CNN says it's a "game changer," and Wolf Blitzer literally said "OMG." Now you know it's a big deal.

As a technical matter, tonight's victories mean nothing. Party rules dictate that none of the delegates to the national convention were determined last night (since the two caucuses were non-binding) and Missouri's primary was literally worthless, since its real caucus is next month. However, Santorum's decisive victories in Minnesota and Colorado — two states where Romney won easily in 2008 — have undercut the inevitability of Romney's nomination and once again underscored his glaring weaknesses among conservatives.

Even Missouri's beauty contest takes on significance it shouldn't have had since it gave Santorum a clean sweep of the evening and allows him to spend the next few weeks saying he has more state victories than Romney so far. (Four to three.) The other warning signs are glowing bright red for Romney as well.

Caucus victories are supposed to be about organization and manpower, two things where Romney allegedly dominates. Yet, he somehow got 19,000 fewer votes in Colorado than he did in 2008, and came in a distant third (more than 10 points behind Ron Paul) in Minnesota. He didn't just lose ... he lost big. He outspends all his opponents by magnitudes, yet has less to show for it.  And as Nate Silver points out, Romney is now 0-for-3 in caucuses and 0-3 in the Midwest, a troubling indicator for the general election.

Last night's results and the continuing slowdown in the primaries also guarantee that Santorum will survive until at least Super Tuesday, giving him three solid weeks of positive juice. (The next Republican primaries are on February 28, though Maine will wrap up its confusing week-long caucus this weekend.) He still hasn't found a way to eliminate Newt Gingrich and unify the anti-Romney vote, but since Gingrich was a non-factor on Tuesday, Santorum should be able to pull some of that support his way. Since Gingrich wasn't even on the ballot in Missouri, it shows how well Santorum can do when he's the only option for those core conservatives who don't believe Romney is one of them. 

As for Mitt, he still has to be considered the front runner, but he's now taken another tough shot to the chin. His poor showing will put him on the defensive, which likely means more negative advertising and more intraparty mudslinging. There will be days of "what went wrong stories" and still more examination of all of the flaws that only seem to seem to grow bigger in the eyes of conservatives. Every day that he has to spend fighting the likes of Rick Santorum is a day he's not fighting Barack Obama and another day where the GOP isn't talking themselves into embracing him as their nominee. Oh, and he got glitter-bombed and crashed his press bus. It was a rough night.

No matter what you think of his chances to be the nominee, in the end it's clear that Romney continues to have a serious problem winning over the most conservative members of his party. Santorum may never get enough overall support to take control of this race, but he's not going to let Mitt Romney have it without a fight.