Liberals and progressives were never OK with his proposing war crimes. The excitement occurs because this happens to be the straw the breaks the camel’s back for a lot of his supporters and some undecided voters. They’re cool when the assaults are aimed at various Others, but when it’s aimed at white women who aren’t necessarily liberals and who could be their own wives or daughters (which some of them additionally regard as chattel) then it’s gone too far for some of them.
If this (and not all the other horrible things he’s said and done) is what it takes for voters to start abandoning him so we’re spared his Presidency then that’s what his opponents and critics are going to drum up. That doesn’t mean they’re cool with either Clinton’s or her opponent’s warhawk statements.
Put another way, when the U.S. government put Al Capone in Alcatraz for tax evasion it didn’t mean they were OK with all the murders he committed and orchestrated.