The filibuster violates the spirit of the Constitution (majority rule), if not the letter.
The Constitution specifically states where supermajorities are required in American governance. The filibuster is not one of them (in fact, it's not even mentioned).
It's time to get rid of it, and let the chips fall where they may.
Sasse is just another GOP-e who would happily spend his entire career in the minority if he could. He'd probably prefer things that way, so he never had to take a stand on matters where his vote might actually change something.