When weird sh!t happens at the extreme end of liberal/conservative institutions, it tends to spread to the nominally-not-so-extreme liberal/conservative institutions. Evergreen may well be a leading indicator.
It's not. TESC has been this way for a long time, it's nothing new to the people of WA. I'm 42 and went to a public university in the state, we all knew what TESC was back then, everyone who went there and goes there knows what they are getting in to. It's certainly not shaping attitudes at other universities.
And this would be entirely convincing, were we living in 'normal' times in the first place. But the whole point that Haidt's article is drawing from is that the level of political factionalization nation-wide is quite unprecedented, at least in recent memory. For freak's sake, Donald Trump is POTUS in case you haven't noticed! Something that The Simpsons used to joke about as obviously crazy and ludicrous! People like to talk about the toxic tendencies on the left (the so-called "SJW's"), but that's hardly the one and only sort of craziness we're experiencing nowadays.