This makes it sound as if Sasse because he’s a principled conservative rejected Romney’s overtures. It seems more like he’s a spoiled brat elitist Freshman Senator who is way out of line about his disdain for Republican voters. Three cheers to Nebraska voters for humiliating him!
Nobody who hopes to ever run for higher office on a Republican ticket is going to mount an independent or third party campaign now.
Sasse isn't noble and isn't dastardly. He's just acting in his own self-interest in not running.
If Romney really is trying to find a #NeverTrump candidate he's going to run up against the fact that nobody who actually has a political future is going to jeopardize it by going against the party's nominee.
Mitt doesn't have much stick-to-itiveness, so he'll get tired soon enough and give up.