The KGB infiltrated the west centers of child indoctrination generations ago, and has stopped generations ago.
While I agree in broad strokes that you're correct, and the KGB infiltration ended mostly with the fall of the USSR in the 80s and that what we have in the west is mostly self sustaining at this point, one thing you may not be aware of is that as early as the 00s and 10s China began their own influence and infiltration efforts against the US, both covert and
overt. There is a reason Wokism resembles Maoist Communism more than it does Soviet Communism, and that is in part due to direct China influence efforts.
As such, cutting off the head would help a bit, but we need to thoroughly fix the academic institutions as well, with the easiest method being tying government funding to showcasing intellectual diversity of thought on campuses, with exceptions for explicitly religious institutions that could then be allowed to maintain a specific intellectual bias. Since Leftists insist their ideology is secular and not religious, this means their bastions will either have to no longer receive any public funding OR they will be forced to diversify their intellectual base and meanwhile explicitly Christian colleges can maintain a Christian worldview without being disadvantaged. Further, if leftist colleges rebrand themselves using, say, Progressive Christianity or Wicca or such to protect their ability to maintain ideological control of the faculty, that ideology is now, legally, tied to a religion and thus falls under the Establishment clause of the Constitution, opening it up to legal challenges the same way teaching or writing laws regarding explicit Christian religious beliefs have been. In short, if they try and take the third option, we turn their own, long, history of jurisprudence against them, which then places them in yet another catch-22, either they get their ideology purged from public areas via the same methods they used to purge Christianity from those areas OR they overturn those cases thus allowing ALL religions back in.
It's a simple solution, though it would require control of the Federal government for long enough to implement and get it to stick.