I don’t see it that way. They are saying that because they know they can’t criticize Moore if they don’t do the same for Clinton. But a cynic would say that it just shows their hypocrisy because they supported Clinton when it mattered and now the are attacking Moore when it matters.
It’s a twofer: They clean the slate for ‘20 and dump the Klintoons and they also get the moral high ground to attack Moore. Win - win for the Demoncats.
Heck....the Pubbies supported Clinton...”when it mattered”.