WASHINGTON — President Obama last week sought to turn attention from health care to immigration — in other words, from one racially divisive issue to another.

Whites tend to hold negative views of Obamacare, while blacks tend to like it. Specifically, 55 percent of whites, an NBC News/Wall Street Journal poll found this year, consider Mr. Obama’s health care law a bad idea, while 59 percent of blacks call it a good idea. On immigration, 51 percent of whites oppose legal status for illegal residents, but 63 percent of blacks and 76 percent of Hispanics favor it.

The statistics mirror the core philosophical division in Washington’s fierce battles over taxes, spending and debt. Whites say government does too much, while blacks and Hispanics say it should do more to meet people’s needs.

Those attitudes, and the continued growth of the nonwhite population, have produced this sometimes-overlooked result: American politics has grown increasingly polarized by race, as well as by party and ideology.