A lot of anti-Ukraine sentiment boils down to anti-west communists who want to see the US collapse at anything/everything (Hasan, leftists, etc) and America first conservatives who are closet Putin supporters (Trump). And both sides have likely been compromised to some degree by Russian influence or money. Both sides have also seemingly taken the position that Putin/Russia can assassinate anyone, attack anyone, start wars etc with impunity and we must not retaliate or criticize because the US is just as bad. Or the US started it.
We literally watched Putin describe the imperialist reasons he invaded Ukraine and nobody had jack shyt to say on the "it's all NATO's fault" side of things. Putin never mentioned NATO.