So the most liberal single university (out of a group picked one of the most liberal regions in the country) matches a statistic that was claimed to be across all universities in the country. I don't know that that's strong evidence that the "statistic [...] is accurate". Even the source you linked indicates that the statistic is far from accurate (and again has the same pattern where for economics professors it's even less).
It's not the best use of statistics that I've ever seen by a long shot, but I just wanted to point out that your claim that it was "bullshit madeup" was inaccurate flamebait.
He didn't say which subset of universities he saw that statistic for. The group of "most liberal universities in the country" includes what, all of the most wealthy and important ones? It's certainly a reasonable subset to consider. The 98% figure is pretty close here (for the group as a whole, not just one like you claim).
You need stronger evidence to attack someone like that, and you don't have it, partially because we don't even know what exactly the scope of the claim was. You could certainly criticize the vagueness of the statement without being toxic.
