Trump and Moore are not a package deal. Flake's utterances are self-serving.
If Trump was THAT BAD, personally, why didn't he endorse Hillary and campaign for her? Lieberman did that for McCain in 2008.
That's why I think the Flakes of the world are full of crap. They don't think Trump is any worse than Clinton on a personal level; they just want their open borders, free trade, and they don't want to "owe" religious types.
When a candidate is THAT bad as the #NeverTrump crowd suggests, it's time to endorse the opposition. That they didn't reflects on THEIR credibility.
Lieberman endorsed McCain in 08 because he was a centrist and felt that McCain had the proper experience required to be commander-in-chief. That's very different than a conservative Republican like Flake coming out and endorsing Hillary, with whom he agrees on almost nothing. Flake wants to improve the Republican Party, not abandon it (as endorsing Hillary would have done).
Hillary was compared to Margaret Thatcher. It's all a matter of perspective.