The Senate on Thursday made an unprecedented change to its rules Thursday night following an extraordinary floor exchange that saw leaders and rank-and-file members spar first over consideration of President Obama’s jobs package, then over a series of non-related amendments and finally over the operating procedure of the chamber itself.

The floor debate – which stretched on for more than an hour and a half in an uncharacteristically full chamber – came as dozens of congressional reporters, aides and lawmakers of both parties were gathering in the Senate Press Gallery on the third floor of the Capitol to bid goodbye to two longtime observers of Capitol Hill: Carl Hulse of the New York Times and Bart Jansen of USA Today.

As the Thursday evening farewell gathering marked the end of an era for many on Capitol Hill, so, too, did the Senate’s unanticipated floor proceedings, which came about as the chamber was considering a bill that would have allowed the U.S. to apply greater pressure on China to allow its currency to appreciate.

“The Senate must have the ability to move forward on legislation that has broad bipartisan support,” Senate Majority Leader Harry Reid (D-Nev.) said in a statement late Thursday explaining his move to change the chamber’s long-observed rules. “A small minority of senators cannot be allowed to bring bipartisan legislation, like a bill to end China’s job-killing, underhanded currency manipulation, to a grinding halt when 14 million Americans are out of work.”

Thursday night’s history-making vote followed more than seven hours of negotiations between the Senate Republican and Democratic leaders.

Both sides said they had reached an agreement to have votes on seven amendments to the China currency bill – a measure that was on track to pass with overwhelming bipartisan support, after a bipartisan group of 79 senators on Monday voted to proceed on the bill.

One of the amendments agreed to by both parties Thursday would have been a procedural vote on Obama’s $447 billion jobs package – technically, a move by Republicans to suspend the chamber’s rules in order to offer the jobs plan as an amendment to the China currency measure.

But just as the leaders appeared prepared to go forward with their plan – and thus let the chamber wrap up its business on the Thursday before a holiday weekend – the agreement got derailed.

Exasperated Democrats charged that Republicans at the last minute tried to introduce a non-related amendment by Sen. Mike Johanns (R-Neb.) regarding Environmental Protection Agency regulations on farm dust. Republicans, just as frustrated, shot back that Democrats were the ones who changed the agreed-to plan at the eleventh hour by trying to substitute the Johanns amendment with one offered by Sen. Rand Paul (R-Ky.) regarding the Federal Reserve.

As the negotiations remained deadlocked, Reid and Senate Minority Leader Mitch McConnell (R-Ky.) got into a rare, unscripted dispute on the Senate floor – with Reid ultimately announcing that the Senate would proceed with a history-making vote.

The procedural ins and outs: Reid raised a point of order against Senate Republicans’ motion to suspend the rules with respect to the seven amendments, including the one sponsored by McConnell on Obama’s jobs package, arguing that the move was intended to slow down passage of the China currency measure.

The chair – speaking on behalf of the Senate parliamentarian – disagreed with Reid’s motion. So Reid then moved to appeal the chair’s ruling, and the Senate voted on whether the chair was correct -- a move requiring only a majority-vote threshold for passage. Democrats overwhelmingly voted that the chair was incorrect, while Republicans (as well as one Democrat) voted in favor of the chair’s ruling.

At one point, Cox Radio’s Jamie Dupree noted via Twitter that “C-SPAN is so confused that all the screen says is ‘This is a procedural vote on the bill.’”

Reid’s action set in motion a precedent-making change. Previously, it had been possible for the majority party to block amendments to a bill but not motions to suspend the rules. From Thursday night onward, it is now possible for the majority party to block both – making it more difficult for the minority to change legislation.

(Worth noting: According to the Senate Historian’s Office, there has been no successful motion to suspend the rules – as Republicans were seeking Thursday night – since 1941. On top of that, the GOP move was on track to fail anyway, given that Democrats who hold a 53-seat majority in the chamber.)

For much of the ninety-minute floor debate, Reid and McConnell debated the roles of the majority and the minority in the Senate, and even the purpose of the chamber itself.

“I feel very comfortable that what we’re doing and what we did today is the right thing to do,” Reid told the chamber, arguing that “cloture means ‘end.’ It’s over with.”

McConnell, pacing back and forth in front of his desk, shot back: “The majority doesn’t want to take votes.”

He then lobbed what many in the Senate might consider the ultimate insult: “We are fundamentally turning the Senate into the House.”

Reid countered: “The Senate should function like the Senate, and I acknowledge that, but we have major piece of legislation being bogged down.”

Later, in a dig at McConnell, he added: “Let’s get back to legislating as we did before the mantra around here was, ‘Defeat Obama.’”

The high-stakes maneuvering – on an evening when most lawmakers had planned on heading back home for a leisurely holiday weekend – played out not before an empty chamber, as most action typically does, but before a Senate half-full with lawmakers, aides and other staffers.

For most of the evening, aside from Reid and McConnell, the senators were silent. Five Democratic lawmakers – Sens. Frank Lautenberg (N.J.), Carl Levin (Mich.), Dianne Feinstein (Calif.), Jay Rockefeller (W.Va.) and Richard Blumenthal (Conn.) – stood attentively in the well of the Senate at one point, their hands clasped in front of them, as the leaders jousted back and forth.

Sen. Sherrod Brown (D-Ohio) sat glumly with his chin on his hand; Sen. Joe Lieberman (I-Conn.) was seated a few rows back with his hands clasped on his desk as if in prayer, his eyes turned upward. On the other side of the aisle, Johanns and Sen. Rob Portman (R-Ohio) whispered to each other in two seats near the back of the chamber; Senate Minority Whip Jon Kyl (R-Ariz.) sat near the front with his hands on his desk, listening to the leaders.

From time to time, the tensions ran so high that rank-and-file lawmakers, too, jumped into the debate.

“I really don’t want to speak,” an exasperated Sen. Bob Corker (R-Tenn.) said upon being recognized by Reid. “Here’s what I want to happen. I think members on both sides of the aisle feel like this institution has degraded into a place that is no longer a place of any deliberation at all. ... (Explain) how the greatest deliberative body, on a bill that many would say was a messaging bill in the first place, ended up having no amendments, and we’re in this place where we are right now.”

Sen. Charles Schumer (D-N.Y.) also rose and mentioned that he had spoken recently with some frustrated Republican freshmen on board “the senator from West Virginia’s boat” and blamed the Senate’s 60-vote threshold for many of the chamber’s problems.

And Sen. Roger Wicker (R-Miss), who acknowledged that he has not often during his four years in the Senate “come down onto the floor and spout out hot air,” spoke out several times Thursday night.

“What we have done tonight is change the rules of the Senate on a messaging bill, on a matter that the majority leader had the votes on,” Wicker said. “That is why I’m so disturbed about the overreaction and heavy-handedness of this move.”

The move by Reid was, of course, unprecedented -- and as of Thursday night, no one could be certain what its consequences would be, or even what such an action might be called. But by the time the chamber adjourned just after 10 p.m., some longtime Senate observers had arrived at a fitting suggestion:

Call it “the Hulse precedent.”