I think that the Millennial cohort (1977 to 1992 births) will be solidly in the Democratic column for quite some time to come, but the post-1993 cohort will probably lean right.
I agree with you for the most part about the voting patterns of different generations. I noticed that most Millennials that I know who remember the Reagan era seem to vote Republican more often than not, while the Millennials that remember the Clinton era seem to vote overwhelmingly Democratic. In addition, several of my co-workers that were born in the mid-1990s expressed support for Libertarian Republicans such as Ron and Rand Paul and Justin Amash.
