Addressed personally to each of the 14 Senators, the note in the pocket-sized U.S. Constitution reads: “A Senator for whom I have great respect, Sincerely, Robert C. Byrd, 5/25/05.”

Byrd gave copies of the Constitution to every Senator who signed on to the bipartisan deal hatched May 23 to avert the “nuclear” showdown on judicial nominations, a heartfelt token of appreciation from an octogenarian Senator who never goes anywhere without his own pocket Constitution.

But for Sens. Ben Nelson (D-Neb.) and Mark Pryor (D-Ark.), their pocket copy is the ultimate sign of their new status as the chamber’s lead Democratic dealmakers. Relative newcomers to the chamber — elected in 2000 and 2002, respectively — Nelson and Pryor cemented their status in the long, tortuous and ultimately successful filibuster negotiations as the go-to Democrats for brokering critical deals with Senate Republicans.

“They were the force that always wanted to go for it,” said Sen. Lindsey Graham (R-S.C.), a solid conservative who embellished his own credentials as a dealmaker by making a late entry and ultimately signing on as one of the “Gang of 14.” “These guys are players — not to undermine leadership, but to do the things that leadership can’t do.”

In a chamber where Democrats hold 10 fewer seats than Republicans, the level of influence that any Member of the minority wields is based squarely on his or her ability to put together a coalition.

And when it’s time for cutting a deal with Republicans, Nelson and Pryor discovered that they only need a few more Democrats on board to actually move things in what has become a bitterly partisan chamber.

While they both acknowledge that this first act of theirs was strictly based on the judicial showdown, they hope that there will be a sequel in the near term as they try to craft centrist compromises to burnish their legislative credentials.

“I think we have developed a partnership,” Nelson said of Pryor in an interview just before the recess. “We can work together.”

“We do need people here who can and will reach across the aisle to get things done,” Pryor said in a similar interview.

In essence, Nelson and Pryor have assumed the role long held by John Breaux, the retired Louisiana Democrat who served as lead Democratic dealmaker through the previous decade. With his Cajun charm, decades of Congressional experience and centrist political orthodoxy, Breaux regularly found himself in the middle of critical debates ranging from health care to tax cuts to energy policy.

One of Breaux’s closest friends in the Senate, Trent Lott (R-Miss.), said there’s still a long way for any Democrat to go to become the sort of honest broker that Breaux was viewed as.

“Replacing John is going to take some time,” said Lott, who has fashioned himself as a dealmaker on the right since losing the Majority Leader’s post. Having worked closely with Nelson in the early stages of the compromise on judicial nominations, Lott said he’s still scouring the Democratic Caucus for the next Breaux, a search that has included the Bayou State’s new senior Senator.

“Mary Landrieu is auditioning to be the next John,” Lott said. “I’m checking her out. She’s a helluva lot cuter than John.”

But many Democratic aides privately noted that Nelson and Pryor were able to do something that Breaux found it increasingly difficult to do in his last years in office: deliver.

Calling himself an “understudy” to Breaux his first four years in the Senate, Nelson has been at the center of critical debates ever since first setting foot in the chamber, from the 2001 tax cuts to every budget resolution fight. And, up for re-election in 2006 in a state that is one of the most conservative, Nelson was a natural to take up the lead role among Democratic negotiators searching for a compromise on the high-profile fight over Majority Leader Bill Frist’s (R-Tenn.) attempt to push the nuclear option.

He sat down with Lott in early January to begin talks about how to avert the parliamentary, party-line move to change Senate precedents and eliminate judicial filibusters. In March, Pryor heard Sen. Lamar Alexander (R-Tenn.) give a floor speech talking about how 12 Senators could seize control of the entire process, if just six Democrats would vote to cut off filibusters and six Republicans would promise not to support the nuclear option.

Soon after, Pryor started talking to other Senators, as well as Lott and Nelson. “The more we talked about that, the more we liked it,” Nelson recalled of the “six-by-six” option.

While Nelson was a natural to assume the role of peacemaker with Republicans, Pryor was an unlikely co-architect. Barely two years into his first term when he started the talks with Lott, Nelson and Sen. John McCain (R-Ariz.), Pryor had never been thrust into the chamber’s spotlight on any national issue.

A plaque on his desk in the Russell Senate Office Building declares to visitors that “Arkansas Comes First.” Pryor, 42, is one of only a handful of Senators who walks the halls always carrying his own bag, projecting an image that he’s ready to work, work, work.

He doesn’t appear to be overly ambitious, deflecting any thought of running for leadership (“I don’t ever see me in the leadership here”) or returning to Little Rock as governor (“No, I don’t really see that happening”).

His father, former Sen. David Pryor (D-Ark.), cautioned him on the filibuster fight back in the spring, warning his son that it was a “hot potato” that might be difficult to handle.

And the son knows from watching his father — whose term of service on the Ethics Committee ran more than 11 years, covering everything from ABSCAM to the Keating Five scandals — that hot potatoes can result in severe political burns. Former Sen. Pryor’s relationship with McCain was nearly ruined over the Keating Five issue, with the two not speaking to one another for almost six years.

It was not lost on Pryor that he worked so closely with McCain on this issue.

“They’re friends again,” he said of McCain and his father, something McCain affirmed.

“His father and I mended that fence long ago,” he said, complimenting Mark Pryor as a hard worker. “The apple didn’t fall very far from the tree.”

While the Nelson-Pryor efforts to some degree undercut the Democratic leadership efforts at blocking all previously filibustered nominees, Minority Leader Harry Reid (D-Nev.) roundly applauded their work for preserving the right to filibuster even if only under “extraordinary circumstances.”

The duo went out of their way to keep Reid posted on the talks, earning kudos from the leader. “Ben Nelson’s always been there,” Reid said of tough negotiations. “Mark Pryor’s just like his dad: quiet, gets a lot done.”

Nelson said the talks that led to the deal hit their most tense moment when the bipartisan group was gathered in McCain’s office on the evening of Thursday, May 19, with most of the group scheduled to leave town the next morning. With no deal at the end of those talks — the ninth meeting of the group in three days — Nelson went home thinking talks were over.

“I was worried the dynamics of a weekend might hurt us. Actually, it helped us,” he said.

By Monday evening, May 23, the group gathered again in McCain’s office, determined to get 14 signatures on a memorandum of understanding declaring a detente on the nuclear option. They had two deadlines in front of them: the scheduled vote the next day on the precedent to eliminate filibusters, and McCain’s premiere of the new television movie based on his book “Faith of My Fathers” across town.

The Senators really wanted McCain to make it there on time, Pryor said. “It sounds small, but we have a lot of respect for John McCain.”

By 7:35 p.m., they had announced their deal in front of the cameras, with McCain impishly plugging his new movie and then handing the stage to Nelson and then Pryor.

“The group learned how to work together,” Nelson said.