Rove only knows polls, so maybe this will help:
In the latest New York Times/CBS News poll, released on Monday, 31 percent of respondents over the age of 40 said they supported gay marriage. By contrast, 57 percent under age 40 said they supported it, a 26-point difference. Among the older respondents, 35 percent said they opposed any legal recognition of same-sex couples, be it marriage or civil unions. Among the younger crowd, just 19 percent held that view.
Just as interesting, support for marriage equality seems to have jumped in the last month or so in the wake of news from Vermont and Iowa:
Forty-two percent of Americans now say same sex couples should be allowed to legally marry, a new CBS News/New York Times poll finds. That's up nine points from last month, when 33 percent supported legalizing same sex marriage.
Polls do change and only time will reveal if this uptick holds. But the generational shift has now been well-documented in many polls.