Well, as someone alive and politically aware during the period, and who's studied that event, no, that Manichean world view doesn't match what happened in the cultural '60s in the least, a period which includes much of the '70s.
For one thing, "those pesky anti-vietnam protesters" had burned down the ROTC building a couple of days before, there was quite a bit of violent rioting prior to the shooting and the National Guardsmen had already had to use their bayonets to manage it (when bayonets get fixed and bloodied you know things got very serious). Today's "campus protests" are utterly farcical by comparison.
In general, violent civil insurrection was common, and the authorities management was very mild by the international standards of the time, and there was plenty of pressure from the bottom up for much more strenuous measures. Note it's the only major incident of that type in that period, and is a trifle when compared to atrocities like Waco.
McCarthy? Please, if you don't know what the phrase "submit to party discipline" means, and that it resulted in every member of the Communist Party of the USA (CPUSA), back when it was popular and selective in admittance (through the '30s at minimum), was a self-declared traitor, well, read up on what the other side was saying, or things like the Venona decrypts which eventually revealed just how accurate McCarthy's raw information was.
And note how the authorities' flaccid response to GRU and NKVD spying through these traitors like Hiss paved the way for crude men like McCarthy. That's a lesson you'll see from the Weimar Republic to a lot of what's happening today, and there's plenty of history of this sort of thing in pre-modern times.
Hoover was a bad apple, I'll grant you, and the rest of the barrel remains rotten to this day; has the FBI Hostage "Rescue" Team ever actually rescued anyone? Latest is their shooting in the only fatality resulting from the Bundy Oregon mess, and then trying to cover that up.