The MN and CO Republican organizations are to the right of the national party, so Santorum's wins, while surprising, are not completely outrageous. Plus , let's face it, they're really irrelevant compared the "swing" states of PA, OH and MI in a general election. What muddies the waters is that Santorum is from PA and may also hold sway in OH, as a result.
Clearly, though, Republican primary voters are self destructing here, a bit like the Dems a few years back. Part of it may be a backlash from "look what McCain got us last time round."