But getting rid of the Obamacare taxes poses two big problems for Republicans. The first is political: The cuts would go overwhelmingly to the richest Americans. The Tax Policy Center, a think tank that leans to the left but whose analyses are generally respected by both sides, estimates that nearly 45 percent of the Senate bill’s tax cuts would go to the top 1 percent of households by earnings. One tax that the GOP wants to repeal, the “net investment income tax,” is even more skewed: 90 percent of its revenue comes from the top 1 percent, and 62 percent from the top 0.1 percent. That has made it easy for Democrats (including former President Barack Obama himself) to tar the Republican plan as a tax cut for the rich.

The tax cuts also create a math problem for Republicans: The more they give up in tax revenue, the more they have to cut spending on health care programs.1 That could make it harder to appease moderate Republicans who want more money to fight the opioid epidemic, smaller cuts to Medicaid and more generous subsidies for low-income Americans to buy insurance.