Just as an anecdote, met a recent state school grad who said he arrived on campus as a dyed-in-the-wool liberal, tried to get into campus activism, and his fellow activists and teachers scared him so much that he's now not sure where he stands politically. Obviously I can't verify this, but for example he had a professor who actively taught that nations are a completely artificial social construct, and as such all im…
But that's a very mainstream position in economics, with much stronger arguments behind it than ideological purity. And it's typically supported by libertarians more than progressives, since the arguments are weakened by strong government-provided social services.
This is what I worry about, when I hear people complain that their views aren't tolerated on campus. Are they really being shut down by intolerant professors who won't accept dissent? Or are they dismissing ideas they don't immediately find reasonable as far-left propaganda and refusing to listen?