WASHINGTON -- Senator Bob Dole had just assumed the mantle of Senate majority leader, after the Republican landslide of 1994, when he confronted a problem.
Piles of Republican legislation from Newt Gingrich's self-styled "revolutionary" House were stacking up in a narrowly divided, more deliberate Senate, and Democrats were threatening to gum up the works with amendments that would stall the bills.
Mr. Dole turned to the Senate's Democratic master of floor procedure, Robert C. Byrd of West Virginia, who taught him a parliamentary trick known to Senate insiders as "filling the tree," Mr. Dole recalled.
The convoluted procedure allows the majority leader to claim all opportunity for offering changes to a bill, effectively preventing any other senator from proposing an amendment intended to slow down legislation or force a politically embarrassing vote.
"I never knew what 'filling the tree' was until I tried it, but it turned out to be pretty good," Mr. Dole said, ruefully accepting a share of the blame for the parliamentary arms race that has consumed the Senate in recent years. "I don't think there's any credit."
The increased use of the tactic, which had previously been rare, is part of the procedural warfare that has reached a zenith over the past two years in the Senate. Republicans threaten to filibuster and propose politically charged amendments, Democrats fill the amendment tree, and Republicans filibuster in retaliation.
The tactic initially meant to speed bills has instead helped slow them down. The Senate -- the legislative body that was designed as the saucer to cool the House's tempestuous teacup -- has become a deep freeze, where even once-routine matters have become hopelessly stuck and a supermajority is needed to pass almost anything.
As a result, the first fight of the next Senate, which convenes in January, is not likely to be over a fiscal crisis, immigration, taxes or any issue that animated the elections of 2012. It will instead probably be over how and whether to change a troubled Senate, members and aides say.
With his majority enhanced and a crop of frustrated young Democrats pushing him hard, Senator Harry Reid of Nevada, the Democratic leader, says he will move on the first day of the 113th Congress to diminish the power of Republicans to obstruct legislation. "We need to change the way we do business in the Senate," said Senator Tom Udall, Democrat of New Mexico. "Right now, we have gridlock. We have delay. We have obstruction, and we don't have any accountability."
The pressure leaves Mr. Reid with a weighty decision: whether to ram through a change in the rules with a simple majority that would significantly diminish Republicans' power to slow or stop legislation.
The changes under consideration may sound arcane, but they would have such a profound impact that they are referred to as the "nuclear option." In effect, they would remake a Senate that was long run on compromise and gentlemen's agreements into something more like the House, where the majority rules almost absolutely.
Critics of the idea, who exist in both parties, say such a change would do great damage, causing Washington to career from one set of policies to another, depending on which party held power.
Senator Mitch McConnell of Kentucky, the Republican leader, said he would aggressively fight any rule change and blamed the Democratic majority for the Senate's dysfunction. "This notion that the Senate is dysfunctional is not because of the rules," he said. "It's because of behavior."
Supporters of the idea, who also do not fit a neat ideological profile, argue that the collegial Senate of the past no longer exists and that American democracy is often paralyzed as a result. Today's Senate, they say, has left crucial positions unfilled, like a confirmed head for the new Consumer Financial Protection Bureau, and is preventing action on major issues like job creation proposals.
"There is a tendency to look to the past through rose-colored glasses, to some mythical golden era when everyone got along and cooperated. That's not true. It's always been tough, and it's always been rough," said George Mitchell, a former Democratic majority leader who would now back some changes. "But I do believe and accept the premise that it's worse now."
Doing almost anything in the Senate today requires 60 votes, because Republicans, who will have 45 seats in next year's Senate, are blocking even procedural motions to begin debating bills or considering nominations. The act of doing so is commonly called a filibuster, although it no longer requires holding the Senate floor for hours.
Both parties bear some responsibility for the changes, experts say, though not in the same precise ways.
Before 1917, senators could delay final votes on legislation by holding the floor and talking. There was no mechanism to stop them, but such filibusters were rare until the debates surrounding entry into World War I. In 1917, the Senate adopted its first "cloture" rule: two-thirds of the Senate could cut off debate on a bill and force a final vote.
Between 1917 and 1971, no session of Congress had more than 10 such votes in its two years. Still, filibusters were common enough that in 1971, Mr. Byrd, a master of Senate procedure, shifted the rules to allow the Senate to take up other legislation during a filibuster.
That change began an escalation of tactics, in which both delays and attempts at circumventing delays have become more common, with one often leading to more of another. Moves by the minority to obstruct bills elicited responses from the majority worsening the environment.
In the 93rd Senate, which met in 1973 and 1974, the number of cloture motions filed -- a rough measure of filibuster threats -- jumped to 31, from an average of fewer than two per Congressional term between 1917 and 1970. Throughout much of the next two decades, cloture votes continued to rise, regardless of which party was in the minority, with many such motions filed in anticipation of filibusters.
"The notion that this started in 2010, I'm sorry, that's so revisionist," said Lauren C. Bell, a political scientist at Randolph-Macon College in Ashland, Va.
But the current Republican minority has taken the practice to a new level. During the past three sessions of Congress, the majority leader has resorted to an average of 129 cloture motions, a near doubling from the level when Democrats were in the minority from 2003 to 2007.
The current Democratic majority has contributed to the parliamentary tit-for-tat, by filling the tree more than in any previous Congress. It has done so over 20 times in each of the last three sessions of Congress. The previous high had been 11, under Republican leadership in 2005 and 2006.
"None of this is new," said Trent Lott, a former Republican Senate majority leader. But, he added, "I'm shocked at how much deterioration has occurred."
Senators from both parties agree that one cause of the trends is the ease with which lawmakers can now bring the institution to a halt. Once the Senate found a way to move on to other business while a bill was being filibustered, senators faced little personal pressure against mounting one. And when the number of votes needed to break a filibuster dropped to 60 in 1975, from 67, the Senate minority could claim that this change allowed for reasonable bipartisan compromise.
But there have been major cultural shifts as well, past majority leaders and academics say. Lyndon B. Johnson once said the Senate was an ecosystem of whales and minnows. Get the few whales and the minnows follow.
The advent of C-Span 2, which put cameras in the Senate in the 1970s, helped turn all the minnows into whales in their own right, Ms. Bell said. The influx of House Republicans in the 1990s, steeped in the partisan fights of Mr. Gingrich, furthered the shift. Republicans and Democrats alike point to a moment in the 1990s when Rick Santorum, then a Republican senator from Pennsylvania and a former House warrior, refused to yield the floor to a colleague when asked, a refusal almost unheard of in the Senate.
The battles over procedure themselves helped corrode the environment. Talk of the "nuclear option" began almost a decade ago, in President George W. Bush's first term. With Democrats thwarting Mr. Bush's judicial nominees, Senator Bill Frist of Tennessee, the Republican majority leader, considered overriding filibusters with a majority vote. Mr. Reid, then the minority leader for the Democrats, fought back. "We believe in following the rules, not breaking the rules," he said. "It will change the Senate forever, and that is not good."
Ultimately, the two parties averted a larger confrontation by a gentlemen's agreement to filibuster judicial nominees under only the most egregious circumstances, as when a nominee is overly partisan or obviously unqualified. In Mr. Bush's first term, the Senate approved 89 percent of his judicial nominees. The rate fell to 74.5 percent in his second term, and was 75.5 percent in Mr. Obama's first term.
In October last year, Mr. Reid took the first step toward going nuclear, a step many of his predecessors have contemplated but never done. Unilaterally dismissing a Republican filibuster, he used a simple majority -- 51 to 48 -- to override the Senate parliamentarian. The parliamentarian had ruled that additional Republican amendments were in order on a China currency bill, even though they were unrelated to it.
Around 40 Democrats -- led by Senators Udall, Tom Harkin of Iowa and Jeff Merkley of Oregon -- have indicated their support for a set of broader rules changes. Two incoming senators, Elizabeth Warren of Massachusetts and Chris Murphy of Connecticut, have also pledged their support. The filibuster would be prohibited on motions to take up legislation or nominations and motions to take approved legislation to conference with House negotiators. A simple majority could approve these motions, which would reduce the amount of time the Senate spends on procedural matters.
Beyond that change, Democrats want to make filibusters harder to execute. Although filibusters would be allowed on final votes to pass legislation or confirm nominees, those conducting them would have to speak from the Senate floor. "It's completely reasonable that senators choosing to argue there should be more debate should have to make their case in public," Mr. Merkley said.
Democrats argue that the changes are modest and will not deny the minority party leverage to block bills and force concessions from the majority. Mr. Reid, who opposed the changes over the last two years, now says he strongly backs them. But he has not said if he will resort to the nuclear option after Republicans almost certainly block the Democrats' initial efforts.
Mr. McConnell says that the power to filibuster a motion to proceed to legislation is the lever Republicans need to negotiate the conditions for debate; without it, the minority party will not have a fair chance to amend bills or to shape the discussion.
Neither side, however, denies that the Senate is dysfunctional.
"There's so much difficulty with comity now," lamented Tom Daschle, a former Democratic majority leader. "Both the majority and minority feel as if their backs are against the wall, and they have no choice but to fight. The majority wants to govern, the minority wants its rights, and those two are almost irreconcilable these days."
This article originally appeared in The New York Times.