True enough, Mr. Obama won the overall female vote by 11 points in 2012—55% to 44%—but that’s hardly remarkable for a Democratic presidential candidate. Al Gore fared the same in 2000, prevailing among women by an identical 11-point advantage. Mr. Obama did better with women in 2008, beating John McCain by 56% to 43%. He enjoyed that advantage even though his first campaign never emphasized “women’s issues” and despite the presence of a woman— Sarah Palin —on the Republican ticket.

A closer look at the numbers reveals that Mr. Obama’s success with the ladies actually stemmed from his well-known appeal to minority voters. In 2012, 72% of all women voters identified themselves as “white.” This subset preferred Mitt Romney by a crushing 14-point advantage, 56% to 42%. Though Democrats ratcheted up the women’s rhetoric in the run-up to Election Day, the party did poorly among the white women it sought to influence: The Republican advantage in this crucial segment of the electorate doubled to 14 points in 2012 from seven points in 2008. In the race against Mr. Romney, Obama carried the overall female vote—and with it the election—based solely on his success with the 28% of women voters who identified as nonwhite. He carried 76% of Latina women and a startling 96% of black women.