Okay a clarification. When I talk about the rift starting 1980 I am referring to high school graduates. Kids born since 1980 do not represent a large enough % of the voting age population to have effected the voting as it has been.
I think I'd wager that the current 18-22 year old range has had a major effect on the voting as it has been. Obama did a pretty good job at getting college kids on board.