It coincides with the election of Donald Trump. This ideology already had a foothold in some departments and Trump was the accelerant that made it spread everywhere.
Longread if you want a more detailed explanation:
https://newdiscourses.com/2021/04/rise-woke-cultural-revolut...
Calling Lindsay a professional mathematician is a stretch. Also he neglects to cite Derrick Bell and Richard Delgado and the whole critical legal studies movement.
