Neither could. Critical race theory isn't prescriptive. Black Lives Matter is, but advocates for equal outcomes (primarily in policing). This isn't Marxism, but just regular justice.
The only thing Marxist about them is that the right has tried to tie them in with Marxism as part of the FUD, and some 'leaders' in the movements also advocate for Marxist solutions. Christopher Rufo was explicit in his intent to do so for Critical Race Theory. It's precisely the same red scare tactics used to punish people with different ideology in the 50s as enemies of the state.
