Who would Sen. Ben Sasse choose between Hillary Clinton and Donald Trump?

If the presidential race were to come down to Hillary Clinton vs. Donald Trump, who would Nebraska Sen. Ben Sasse pull the lever for?

I’ve been asked recently who I'd support between Trump and Hillary.
My answer: neither of them.

— Ben Sasse (@BenSasse) February 29, 2016

If Trump becomes the Republican nominee my expectation is that I'll look for some 3rd candidate – a conservative option, a Constitutionalist

— Ben Sasse (@BenSasse) February 29, 2016

Sasse’s “open letter to Trump supporters” can be read on his Facebook page.