Well obviously, or Jeb would have been the Republican nominee. With that said, it is very obvious that GOP put itself on the "wrong" side of the culture war for many Millennials and there will be a price to be paid for that in conservative brand erosion. Jon Stewart was the guy making the most hay out of this, but a lot of what we would normally consider "entertainment" media (compared to news media) pilled on with him. They made being "progressive" cool, a single generation removed from when the word "liberal" became toxic.

2/3rds of Millennials don't see themselves as religious:

And there is evidence that many Millennials were driven from religion by the culture wars:

quote:
Among Millennials who no longer identify with their childhood religion, nearly one-third say that negative teachings about, or treatment of, gay and lesbian people was either a somewhat important (17%) or very important (14%) factor in their disaffiliation from religion.

Source

Overall we see a clear trend over time among all adults that those without religion more and more identify themselves as liberal:

So I think it would be folly to assume that Millennials back Sanders because of how well their family did in comparison to the Bush years. If that was the case then we would see them supporting Hillary (who is trying to position herself as a continuation of Obama's policies) in greater numbers.

Instead we see Millennials push back on Obama, and Hillary, and embrace a much more progressive politician. They are doing that because they as a generation ARE more liberal, and a big part of the reason they are is because the cultural wars (especially gay marriage) pushed them there. Jon was just a cheerleader on the sidelines of that now lost war who Millennials trusted much more than "traditional" figures of authority. It wasn't all his fault of course, but he was the best at articulating the brand damage being done.