Mr. Christie’s budget speech, delivered less than a year before he will be up for re-election, at times sounded like a campaign pitch to the voters of this overwhelmingly Democratic state. Advocacy groups had lobbied hard for the Medicaid expansion, and Democrats in the Legislature applauded it.

But it also reflected Mr. Christie’s national ambitions and his continued push to present himself as a different kind of Republican — one who could teach Washington a thing or two about bipartisanship. He talked about how he had “turned Trenton upside down” in his first three years, ending what he described as the tax-and-spend ways of his Democratic predecessors. His proposed budget of $32.9 billion is an increase of about 4 percent over the one approved last year, but he emphasized that the state will spend less than it did in the 2008 fiscal year.

Accepting federal money for Medicaid, he said, would save the state $227 million in the fiscal year that begins in July. Earlier this month, the governor showed his opposition to the health care law when he declined to establish a state-run exchange to allow people to buy health insurance, insisting that the federal government would have to do it.

Under the new law, the federal government pays the full cost of Medicaid expansion for the first three years, and 90 percent of the cost after that. The governor said in his speech that he would end the expansion if, “because of adverse actions by the Obama administration,” it no longer made fiscal sense.

Still, the partial embrace by one of the country’s most prominent Republicans was a boost to the president’s health care program. It came a week after Gov. Rick Scott of Florida, a former health care executive, reversed his previous position and joined a number of Republican governors taking federal money to expand Medicaid. The Supreme Court ruled last year that though the law was constitutional, states could choose not to expand their programs.