One potential complication for President Obama’s embrace of gay marriage is that minority voters at the core of the modern Democratic electoral coalition have usually resisted the idea more than whites. But that gap is narrowing-driven mostly by the same process of shifting generational attitudes evident among whites.

In the latest Pew Research Center measure on gay marriage from April, for instance, attitudes toward gay marriage converged among whites and non-whites: in both groups, 47 percent supported it, and 43 percent opposed it. In both communities that represented enormous movement from as recently as 2004, when President George W. Bush’s re-election campaign encouraged state-ballot initiatives to ban gay marriage as a means of mobilizing conservative voters. At that point, in Pew polling just 31 percent of whites and non-whites alike supported gay marriage. Through 2010, support grew more rapidly for whites than non-whites, Pew found, but in the past two years, the minority numbers have increased more quickly, producing the intersection evident in the latest survey. (Gallup Polling also shows that attitudes toward gay marriage have converged in the white and minority communities, with each group divided about in half over the question.)