So much for the era of good feeling in the U.S. Senate.

After weeks of fighting, a pact among Republican and Democratic moderates to forestall a meltdown over judicial nominees (search) seemed to hold promise for a new period of cooperation.

"I think the good faith and the mutual trust that we have achieved here will carry over into this Senate on other business as well," said Ben Nelson, a Nebraska Democrat who was one of the 14 senators who forced the agreement on leaders of both parties.

That was Monday. Three days later Democrats united to delay the confirmation of John R. Bolton (search) as U.N. ambassador, and the recriminations started right up again.

"This filibuster is particularly disheartening after all the expressions of good faith," said Sen. Jon Kyl, R-Ariz.

It was probably a stretch to think the sense of relief and euphoria — at least in some quarters — would carry over into other business in the polarized Senate.

Just because a crisis over President Bush's judicial nominees and Democrats' use of filibusters (search) to block them was defused, that didn't alter the fact that the chamber remains deeply divided and riven with distrust.

"It was fatuous to suggest that this would ripple over to Social Security reform or anything else," said Thomas Mann, a senior fellow at the Brookings Institution. "The parties remain ideologically polarized and they're going to do battle."

Sen. Orrin Hatch, R-Utah, called the deal by 14 senators a "truce, not a treaty," suggesting that the nuclear option — the catch phrase for a Republican proposal to strip Democrats of their right to block final votes on judicial nominees — can be taken off the shelf.

Minority Leader Harry Reid, D-Nev., said the vote Thursday denying the supermajority required to end debate on the Bolton nomination was not a filibuster. Instead, Democrats were using what leverage they had to try to get the administration to supply additional information about Bolton.

Still, the stalling of action on Bolton's nomination came only hours after Reid gave a speech at the National Press Club calling for bipartisanship and saying the deal on the nuclear option gave hope for a new bipartisan beginning for the Senate.

In his speech, Reid said the deal on judges "doesn't have to be an isolated incident — a momentary cease-fire before Washington's trench warfare starts up again. Rather it can be a new beginning.... Just as there was a bipartisan majority that could not stomach the nuclear option, there is a bipartisan consensus for action on many fronts."

But Reid also presides over a Democratic caucus energized against the combative Bolton and incensed over the White House's refusal to turn over classified information about the embattled nominee. Those feelings didn't change simply because the crisis over judges was averted.

Thursday's vote on closing the debate on Bolton stirred up hard feelings between Senate Majority Leader Bill Frist, R-Tenn., and Reid, who, despite the imbroglio over judicial nominees, have a good working relationship.

The Frist camp charged that Reid had assured Frist on Wednesday night that enough Democrats would vote with Republicans to let the nomination go forward, and Frist was sandbagged Thursday when Reid warned him just hours before the vote that the nomination would stall.

"It's not the fact that it was done, it's the way it was done," said Frist spokesman Bob Stevenson.

Reid's spokesman, Jim Manley, said Reid had never guaranteed Democrats would supply enough votes — when combined with 55 Republicans — to produce the 60 votes required for the Bolton nomination to advance to an up-or-down vote. He said Reid had urged Frist to postpone the vote until June.

Just as the good will engendered by the deal on judges seemed to dissipate quickly, there's a chance the hard feelings stirred up by the Bolton vote will fade too.

And Republicans can take some solace that three of the seven Democrats who signed the agreement on judicial nominations — Nelson, Mark Pryor of Arkansas and Mary Landrieu of Louisiana — voted to advance Bolton's name toward final approval.

"The Bolton nomination is hardly a test of what the group set out to do or what the agreement means," said David DiMartino, a spokesman for Nelson.