WASHINGTON — Senate Republicans, who have promised a repeal of the Affordable Care Act for seven years, took a major step on Thursday toward that goal, unveiling a bill to cut Medicaid deeply and end the health law’s mandate that most Americans have health insurance.
The 142-page bill would create a new system of federal tax credits to help people buy health insurance, while offering states the ability to drop many of the benefits required by the Affordable Care Act, like maternity care, emergency services and mental health treatment. 
The Senate bill — once promised as a top-to-bottom revamp of the health bill passed by the House last month — instead maintains its structure, with modest adjustments. The Senate version is, in some respects, more moderate than the House bill, offering more financial assistance to some lower-income people to help them defray the rapidly rising cost of private health insurance.
But the Senate measure, like the House bill, would phase out the extra money that the federal government has provided to states as an incentive to expand eligibility for Medicaid. And like the House measure, it would put the entire Medicaid program on a budget, ending the open-ended entitlement that now exists.
It would also repeal virtually all the tax increases imposed by the Affordable Care Act to pay for itself, in effect handing a broad tax cut to the affluent, paid for by billions of dollars sliced from Medicaid, a health care program that serves one in five Americans, not only the poor but almost two-thirds of those in nursing homes. The bill, drafted in secret, is likely to come to the Senate floor next week, and could come to a vote after 20 hours of debate.