The John Jay College professor and anti-fascist activist whose tweet about teaching "future dead cops" sparked an uproar from law enforcement has now set his eyes on Mayor Bill de Blasio. Michael Isaacson accused the mayor of "mess[ing] up big" by "tak[ing] a swipe" at the school's autonomy and "free speech and academic freedom."

In late August, Isaacson tweeted, "Some of y'all might think it sucks being an anti-fascist teaching at John Jay College but I think it's a privilege to teach future dead cops." The tweet remained under the radar until Isaacson appeared on Tucker Carlson's Fox News shows to talk about the antifa movement on Thursday. According to the Daily News, "The tweet caught the attention of police union officials after the 29-year-old anti-fascist leader appeared on Fox News... Three union bosses and Police Commissioner James O’Neill slammed Isaacson’s tweet."

Some of y'all might think it sucks being an anti-fascist teaching at John Jay College but I think it's a privilege to teach future dead cops — Mike Isaacson (@VulgarEconomics) August 23, 2017

Isaacon was suspended and, on Friday night, de Blasio Tweeted, "New York City won't stand for the vile anti-police rhetoric of Michael Isaacson and neither should John Jay College"—which the professor responded to on Saturday.

First @NYCMayor has taken a swipe at the administrative autonomy of John Jay College and CUNY — Mike Isaacson (@VulgarEconomics) September 16, 2017

Second, @nycmayor has taken a swipe at free speech and academic freedom — Mike Isaacson (@VulgarEconomics) September 16, 2017

Third, @NYCMayor is placating PBA with a costless symbolic demand to avoid having to meet the MATERIAL demands in contract negotiations — Mike Isaacson (@VulgarEconomics) September 16, 2017

Keep in mind this is the same @NYCMayor who was protested by that same PBA for balking on a 1% pay increase. Who's really anti-police here? — Mike Isaacson (@VulgarEconomics) September 16, 2017

Isaacson told the NY Post that he left the city after receiving many threats (many of which he shared on Twitter), "I was not really considering that people would take this seriously." He aded, "The content of the tweet is a fact, because I teach police and everybody dies, including police."

He did find some levity about it:

Actually I lied. I love the memes. The pez dispenser was my fav so far pic.twitter.com/XH24De2KZP — Mike Isaacson (@VulgarEconomics) September 18, 2017