Tight restraints on filibusters were championed by less-senior Democrats like Sens. Jeff Merkley, D-Ore., and Tom Udall, D-N.M. They are frustrated with the chamber's often glacial debates and the ability of the minority — these days Republicans — to kill bills with less than majority support.
"Are they everything I want? Of course not," Udall said in an interview. But he said the Senate is "moving in the right direction. With these changes, it will make this a more efficient institution."
In an email to supporters, Merkley called the agreement an improvement but also complained that senators delaying legislation would not have to appear on the Senate floor.
"If senators want to force more debate, they should make their case before the American people so the public can weigh in on whether the filibusterers are heroes or bums," Merkley wrote.
More veteran Democrats like Sen. Carl Levin of Michigan were reluctant to stifle the tactic, mindful that his party could find itself in the minority after any election and would want to be able to use the maneuvers.
The liberal group Common Cause, which has filed a lawsuit challenging the constitutionality of the filibuster, criticized Reid for the agreement, saying the senator "has gone missing in the fight for filibuster reform."
Democrats say Republican use of the tactic has become almost routine and far too frequent. Republicans say they use it because Reid often blocks them from offering amendments.
As part of the agreement, filibusters could be avoided when the Senate tries beginning debate on a bill or nomination. In return, the majority leader would have to allow each party to offer at least two amendments — addressing a major complaint of Republicans that their amendments are often shut out.
In addition, once the Senate votes to limit debate on certain nominations — district court judges and administration posts below Cabinet level — the debate would be limited to two hours, far below the 30 hours now allowed. The proposal was aimed at speeding the time spent on such nominations.
In addition, instead of three separate opportunities for opponents of a bill to wage filibusters to block a Senate vote allowing the chamber to try writing compromise legislation with the House, there would only be one such filibuster allowed.
According to the Senate Historian's Office, there were 73 "cloture" votes to end filibusters in the two-year Congress that ended earlier this month. There were 91 such votes in the Congress that served in the two previous years, and 112 in the two-year Congress before that. Republicans were the Senate minority party in each of those Congresses.
Those are the three highest number of cloture votes in any Congress since the Senate started allowing such votes to end filibusters nearly 100 years ago.
Associated Press writers Jim Abrams, Stephen Ohlemacher, Andrew Taylor and David Espo contributed to this report.