One reason is the fundamentally different partisan backdrops to the health and welfare debates. Mr. Clinton had campaigned on promises of welfare reform, traditionally a Republican priority, to brand himself “a different kind of Democrat” at a time when his party was struggling to compete in presidential elections.

That set up Mr. Clinton’s compromise with a Republican-led Congress. On health care, by contrast, a Democratic president pushed a longstanding priority of his party through a Democratic-controlled Congress.

Another reason is the rightward ideological shift in the Republican Party. The health law pushed by Mr. Obama strongly resembled a plan that Republican leaders themselves once proposed as an alternative to the 1993 plan that Mr. Clinton had offered in vain.

Republicans unanimously opposed Mr. Obama anyway, with a zeal that has not ebbed four years later.

“In the old days, like when I ran Medicare, when we had this kind of conflict in what appeared to be the intent versus the actual wording, we would go in and ask Congress for a rifle shot to clarify in the statute what needed to be said,” said Gail R. Wilensky, a Republican health care expert who served in the administration of President George Bush.

Instead, House Republicans who have repeatedly voted to repeal “Obamacare” vow to try again with the new Republican majority in the Senate. And a dispute that legislative aides once would have resolved with minor editing has been turned over to Supreme Court justices.

“In my experience there’s never been a controversial major piece of legislation that didn’t get followed by a technical change,” said Representative Henry A. Waxman, Democrat of California, who is retiring after a 40-year House career renowned for legislative craftsmanship.

“It’s become very difficult to legislate on any subject,” Mr. Waxman added. “On this one, it’s become such a part of the ideology of the Republican Party. They never wanted to change the law. They just want to stop it.”