The Republican primaries have been all about Mitt Romney and Newt Gingrich for weeks now, but Tuesday's contests in Colorado, Minnesota and Missouri gave Rick Santorum a big chance to shine. Santorum won all three contests. While the races were nonbinding, with delegates to be allocated later at district and state conventions (and in the case of Missouri, at the state's real caucus next month), that doesn't mean they don't matter. They still go a long way in terms of providing political momentum, media attention and bragging rights. Let's take a closer look at the results.

Colorado

Even though Romney, who won the state four years ago, was expected to win in Colorado, Santorum won instead with 38 percent of the vote. Romney came in second with 36 percent, followed by Gingrich and Ron Paul, but the state's evangelical population likely gave Santorum the edge.

Minnesota

Santorum also had a solid victory in Minnesota. Paul came in second, followed by Romney and Gingrich. The caucus format, which tends to draw small, devoted followers, rewarded Santorum's heavy campaigning in the state (including a visit to the factory that makes his favorite sweater vests).

Missouri

Santorum swept the race in Missouri. Romney came in second place, and Paul third. Gingrich, who failed to file the necessary papers on time, wasn't on the ballot. But Santorum's other wins still strengthen the argument that he, not Gingrich, is the most viable "Not Romney" candidate. At the very least, it poses a challenge to Gingrich's not-so-long-ago call for Santorum to drop out of the race to make room for so-called stronger contenders.

What Does It Mean?

Santorum's three-for-three wins highlight Republican voters' resistance to fully embrace Romney as the front-runner, and the Obama campaign is thusly characterizing the night more as a Romney loss. Democratic officials don't appear to be paying Santorum any mind, continuing their usual business of cranking out anti-Romney messaging.

"Tonight was a bad night for Mitt Romney, plain and simple," Democratic National Committee Chair Debbie Wasserman Schultz said in a Tuesday night statement. "Republicans are giving the field of candidates another look, demonstrating that the more people get to know Mitt Romney, the less they like him. They know he'll say anything to get elected, and they don't want a candidate they can't trust."

But with a few weeks to go before the Arizona and Michigan primaries, more twists may be ahead -- and all candidates should be advised not to take anything for granted.

Cynthia Gordy is The Root's Washington reporter.