If you subscribe to the coming of age theory, there's a small cohort born between about 1992 and 1997 that would have been too young to be swept up in the "hope and change", but already have been politically aware before Trump. You can also see it in a somewhat decreased level of activism on college campuses between 2011 and the spring of 2016. I'll also note that, in 2016, the 18-24 vs. 25-29 polarization was not so apparent. There was also a Washington Post article claiming that Mitt Romney outright won 18-20 year old voters in 2012, but that's probably impossible to truly know.
I don't believe this at all. Also, speaking as someone who was in this age cohort in 2012 (and in college during the 2011-2016 period you're referring to) there was still very much a pro-Obama sentiment on campuses as well as left-wing activism which you could maybe refer to as the start of a certain type of woke culture.
Poll
