The compromise included language, in response to objections by then-Attorney General Ken Cuccinelli, which provided for a sum-sufficient appropriation of federal funds to pay for expansion. The budget deal required approval by three-fifths of the representatives of each chamber on the new Medicaid Innovation and Reform Commission.

Conservative opponents contended that the appropriation language was hidden in the budget — supporters noted that it was debated in each chamber in the waning hours of the 2013 session — and could allow McAuliffe to expand Medicaid or a private insurance alternative without legislative approval.

After a pitched battle in closed-door meetings, three Republican senators who support expanded coverage agreed last week to an amendment that stripped the sum-sufficient appropriation from the budget and inserted a provision that requires an appropriation by the full assembly to fund expansion.

The senators were spooked by House Republican leaders who warned that the budget might die in the House without the amendment or if it left the Senate without significant Republican support. The Senate approved the amendment on a party-line vote, and the revised budget passed with one Democrat in support in each chamber.