Well, these people do need to be evangelized.
But, the first thing we have to do, is make sure that our own children don’t go to such institutions. That’s just my opinion. But, as you said in the OP, these liberal academia professors lead many people astray. The first step is for us personally to send people a clear message by how we live our lives… a message that Catholic/ private Christian schools/ homeschooling is a viable alternative to secular education.
I should say that I myself am a college student at a secular institution. And, I’ve been in public school my whole life. Having gone through it, especially in college, many of the professors are known to be card-carrying members of the Communist party. They are radical. Yet, their views are taught as normative. [And no, they don’t preach Communism… or are overt about any of their heresies… but its pervasive in the curriculum, and it seeps through].
To evangelize these professors, the first step is praying for them. But, in the meantime, we need to be doing all we can to take away these peoples’ influence. By promoting Catholic schools, etc. These peoples’ views deserve to be put on the margins of education. They once were, and they can be made so again, eventually.