Yet another sign that America will outgrow disagreement about LGBT rights arrived Monday from the Pew Research Center, which found 69 percent of 18- to 29-year-olds support same-sex marriage, versus 54 percent of people overall. Unsurprisingly, young people who lean Democrat favor gay marriage the most heavily; 77 percent are pro. But the most interesting data is on the other side of the aisle, where 61 percent of 18- to 29-year-old Republicans say they support legal marriage for same-sex couples—a 39-point gap over Republicans 65-and-over.
Generational change may be the defining issue of contemporary politics. As Jonathan Chait wrote last week at New York, "in previous elections, age didn’t matter very much—the young and old voted in mostly similar ways. But a generational cleavage started opening in 2004, and has remained unusually wide. ... [Y]ounger voters are simply much more liberal than their elders across the board." That said, the boom in support for gay marriage in the last decade has been too rapid to come from the generational gap alone. My colleague Jonathan Cohn pointed out last month that attitudes have changed within generations, too. Of the 16-point growth in support that marriage equality experienced between 2004 and 2011, about one-quarter can be attributed to the rise of Millienial voters. The graph below, from Pew, suggests there's more where that came from.