Hmm, I'm not sure about this. In fact, I'd argue that liberals have always been a little more susceptible to groupthink than conservatives. I think it's a natural consequence of the Left's tendency to be more oriented towards groups and the Right's tendency to be more oriented towards individuals.

The problem is that right now, the dominant narrative on the Left (mainly because, as you say, too many people are spooked by the consequences of countering it) is to uphold a twisted vision of kindness that places identity above all else. Even objective reality.

So people who challenge it have to risk positioning themselves not only as illiberal but evil.