Collins is the last of a dying breed in DC - the centrist Republican.  She's miles away from the Inhofes and Santorums of the world, and increasingly disenfranchised within her party.  (Also increasingly northeastern: Sununu (NH), Snowe (ME) and Chaffee (formerly RI) are comparable.)

The dems don't have a monopoly on good policy ideas in Washington, and good policies rarely come out when one party dominates DC.  The republicans have been captured by their rabid idiot wing and need a thorough thrashing in November if they're going to reformulate themselves into something productive.  But if and when they do, I sure hope that there are folks like Collins within the party to lead them out.  

(Also worth noting that in my personal dealings with DC, I have found Collins office to be very thoughtful on energy & environmental issues, and she is generally an asset to our community.)

That doesn't mean she's perfect of course.  But good long-term policy needs people like her in DC, notwithstanding Alito, Roberts and (politically understandable, even if intellectually indefensible) support for her party's VP candidate.