For more than a year, politicians have been fighting over whether to raise taxes on high-income people. They rarely mention that affluent Americans will soon be hit with new taxes adopted as part of the 2010 health care law. The new levies, which take effect in January, include an increase in the payroll tax on wages and a tax on investment income, including interest, dividends and capital gains. The Obama administration proposed rules to enforce both last week. Affluent people are much more likely than low-income people to have health insurance, and now they will, in effect, help pay for coverage for many lower-income families. Among the most affluent fifth of households, those affected will see tax increases averaging $6,000 next year, economists estimate.