The documentary Hypernormalisation talks about the strategies Bezmenov lines out the four basic stages from a slightly different angle. Worth a watch. Things have gotten even more frightening since this warning. Bezmenov talks as if it's only the left that's targeted by ideological subversion, and maybe that was the primary strategy at the time, but it sure seems like both sides are are in play now.
I wish there were literature or media on the subjects that Curtis covers. I find Adam Curtis is more focused on making entertaining docus than explicitly informative. On occasion in other docs he's made some claims of fact on topics that have more nuance than "yes" or "no".
Also the video posted here is just an excerpt. The full version (1h20 something) is much more clear about how the KGB was considering the left according to him.
Not much in office, no. But say, on US academic campuses you'll find lots of people even in the 21st century who still claim to be Marxist. The traditional Left definitely exists in the US as a subculture.
https://www.filmsforaction.org/watch/hypernormalisation-2016...