No thought control is required to explain this phenomenon
Kids (especially those in college, for some reason) tend to be more liberal. In the 70s, believe me, no one in college admin shaped our (liberal) opinions. The opposite was true.
As people get older, they become more conservative. Ronald Reagan is a great example of this process. I do not believe that he was deluded by any college conspiracy, in his early liberal years.
Compared to the 60s and 70s, this is nuthin! If we attempt something silly, like occupying Afganistan, expect some real fireworks on our campuses.
As far as people with opposing views being shouted down, kids tend to be rude, too. Anyway, the shouting-people-down tactic, is not used by the yahoos on the left more than the yahoos on the right.