Start laying off professors?
Start laying off liberal professors. My engineering, math or physical science were ALL either conservative (when their politics were knowable), or apolitical. They stuck to the subject matter. I only encountered liberal proselytizers in the humanities departments. And, to be fair, most were apolitical or did not use their lectures to espouse their views. However, there were a few......
I have no idea how it is today in the University. That was 40 years ago. :)