Rubbish. I've never seen "liberals" here suggest previous US administrations weren't flawed or never made shit decisions with negative consequences at home and abroad. But they recognise that the Trump administration and compliant/complicit/collaborating GOP Congress represents a whole new level of fucked-up-edness. Those already the most disadvantaged within and outwith the US will suffer the most from their policies (e.g. climate change denial, ending funds for women's reproductive health, stoking racism, Islamaphobia, homophobia, etc.) And, gee, you know, they'd like to stop this happening.
But those who fixate on "political purity" won't lower themselves to do any heavy lifting lest they be tainted from proximity to those goddamned goody two shoes bleeding heart liberals. Better to admire those plucky, establishment poking Trumpaphiles, and toast a few marshmallows as the world burns. Yep, sure.