Britain Has Free Healthcare - Why Not Us?

The Washington Monthly Kevin Drum expresses frustration with those who claim socialized health care in Britain is bad, figuring it can't possibly be much worse than here, and it's free, so what's the problem. There follows 198 comments of various levels of cluelessness of the "is not/is too" variety.
What Drum and apparently all his readers (left and right) are incapable of seeing is the obvious reason National Health Care will never be adopted in this country. White Americans don't like the idea of supporting non-White Americans, and most whites are fairly certain that non-whites will not be paying their weight. Since non-whites make up about 30% of the population but earn about 15% of the income, this is not an entirely irrational concern. But the problem is we're so segregated. Thus the idea of universal healthcare typically invokes visions of everyone's local GP's office suddenly morphing into a South Central methadone clinic.
You can make all the comparisons to British healthcare you want. Everyone knows that Britain has a small number of non-South Asian minorities (who of course don't count as real minorities) and, being an island, doesn't have 250 million Mexicans on the other side of a 3-foot roll of barbed wire ready to scoot over for some TLC.