“We’ll have to see, but I think it was certainly unfortunate,” said Senator Susan Collins, a Maine Republican who has often worked with Democrats.

Senator Mitch McConnell of Kentucky, the Republican leader, made clear that he hoped to exact the ultimate revenge, taking back control of the Senate and using the new rules against the Democrats who made them. “The solution to this problem is at the ballot box,” he said. “We look forward to having a great election.”

David Axelrod, a former top adviser to Mr. Obama, said retaliation by Republicans against the president’s broader agenda would end up hurting them more than Democrats. “If their answer is, ‘Oh yeah, we can make it even worse,’ I think they do that at great risk,” Mr. Axelrod said. “They have to make a decision about whether they want to be a shrinking, shrieking, blocking party, or if they are going to be a national party.”

From the moment Mr. Obama took office, the president who proclaimed that there was no red America and blue America, only the United States of America, has strained to maintain some pretense of bipartisanship — through protracted and fruitless efforts to woo Republicans on his economic stimulus plan and health care law, through dinner dates with some handpicked Republican “friends,” through the nomination of Chuck Hagel, a former Republican senator, to lead the Defense Department.

In the raucous and dysfunctional House of Representatives, any bill, no matter how inflammatory, has been dubbed bipartisan so long as it attracts a handful of Democratic votes. While Senate leaders have held up for praise any legislation that has secured strong bipartisan majorities — a farm bill, an immigration overhaul, a reauthorization of the Violence Against Women Act — Democrats have seethed as one presidential nominee after another fell to procedural blockades and major initiatives like gun control collapsed when they could not reach the 60-vote threshold.

Then on Thursday, before a solemn, almost funereal gathering on the Senate floor, the pretense came to an end.

“It became clear even to reluctant members that their strategy of gridlock helped them more than us because we are the party that believes government has to be a force for good,” said Charles E. Schumer of New York, the third-ranking Senate Democrat.