We're so used to it we can forget what it says about the party as a whole:

If Obama nudges past 80 percent among minorities (which seems very possible) or the minority vote share rises (also possible, though less probable), the president could gain reelection while winning only about 38 percent of white votes. Conversely, if the white proportion of the vote increases just a single percentage point (to 75 percent), and Romney records any gains among minorities, he could shave his winning number to a more manageable 59 percent of whites.

On its face, the math is tougher for Romney. If he reaches 61 percent among whites, he would equal the best performance ever for a Republican presidential challenger with that group of voters: Dwight Eisenhower in 1952, Ronald Reagan in 1980, and George H.W. Bush in 1988 each won between 56 percent and 61 percent of white voters, according to polls at the time.

Obviously a mixed race president affects this – but not that much. John Avlon has a great primer on how this loss of diversity among Republicans has only accelerated recently, especially with draconian rhetoric on Latinos. And Romney, in stark contrast with his father, seems deeply uncomfortable around anyone but white, handsome, heterosexual males. His veep choice looks like one of his sons – hardly a sign that Romney even understands how culturally isolated he is.

More to the point, a country that has two major parties, one of which has almost no appeal to racial minorities, is not a stable or rational one. Before Nixon's consolidation of the South, both parties had admixtures of race that allowed for mutual communication. Since then, the GOP has steadily become the white Southern party, and only the Democrats are able to have a racial mix close to the country as a whole. That's something Republicans should be ashamed of. But it's not something the Democrats should be gleeful about. It's a national tragedy – another reason why this polity is in danger of coming apart at the seams.