Democrats, who had passed the seven-year-old system known as Obamacare without a single Republican vote, say that the GOP proposal to repeal more than 20 taxes enacted under the law amounts to a windfall for the rich and for corporate interests.

The Republican plan also probably would make Medicaid, the program that provides coverage to the poor, less generous.

Overall, it would be “a big transfer. This is a massive tax cut for unpopular industries and wealthy individuals,” said Andy Slavitt, who was acting administrator of the Centers for Medicare and Medicaid Services during the final years of the Obama administration. “It is about cutting care for lower-income people, seniors, people with disabilities and kids to pay for the tax cut.”

Meanwhile, conservative critics argue that the blueprint goes too far the other way. In their view, for instance, the individual tax credits included in the Ryan-backed plan to offset the cost of insurance are actually a new entitlement, not all that different from the subsidies provided under the Affordable Care Act.