Yeah if anything the one bad consequence of left crit of democrats is that it could make apolitical people more vulnerable to criticism of democrats from a far right, populist, perspective. But as long as we make sure to be loud and clear about the fact that both parties are leading to losses for the working class and gains for the ruling class, and fascists will do nothing to ameliorate that except pay lip service to middle class white people, there's no reason why we'd make anyone embrace conservative opinions. That comment was incoherent garbage.

Edit: to clarify what I mean by the first sentence, the way most apolitical people will start to form their opinions will be to just pick a side from one of the two acceptable ideologies, because that's the way you consume politics in America. If we were to only focus on criticizing Democrats and never Republicans, (which to be clear I don't believe to be the case, I see no shortage of criticism to either party) as material conditions worsen and more people start to pick a side they'll be more likely to swing toward fascism, unless socialism somehow becomes a mainstream and acceptable ideology.