Sen. Tom Udall pledged Thursday to return to the Senate floor in January 2015 to make another effort to overhaul the chamber’s rules, and he expects to have new reinforcements supporting his effort.

Udall noted that new Democratic senators elected in 2012 actually campaigned in support of curtailing filibusters in the Senate.

“There was a real passion in terms of changing the rules, changing the way the Senate works and I really give — this class of senators that came in the 113th a lot of credit for how far we moved,” the New Mexico Democrat said.

Udall, who helped spearhead the effort that led to modest changes to the Senate filibuster rules this past January, told a group of political scientists, journalists and congressional staffers that he would track the way that the Senate functions over the next two years before making a determination as to exactly what to propose at the start of the next new Congress.

In general, new Democratic senators replacing longtime chamber stalwarts have expressed more willingness to use what supporters call the constitutional option to change the rules with a simple majority vote at the start of a new Congress. GOP opponents of such a move have called it the “nuclear option.”

Udall said that the modifications made in January, no matter how incremental, represented the first substantive shift since 1975.

“I think that it will continue to be that you will have this debate within our caucus … as to what it would be like if we were in the minority, and everybody knows we’re going to be in the minority. The history of the Senate says every six to 10 years you change back and forth.”

Udall also encouraged a coalition of outside groups to keep beating the drum in favor of changes between now and the start of the next Congress in 2015, including by raising the issue during the special election in Massachusetts to fill the seat formerly held by Secretary of State John Kerry.

“Let’s talk about this throughout the year,” Udall said. “I think we need to take circumstances that we have throughout the year and highlight those and to once again keep talking about rules reform.”

While many outside the Senate have doubted Majority Leader Harry Reid’s commitment to actually changing the way the Senate operates, Udall said that at the end of the day, the Nevada Democrat did not have the votes to deploy the constitutional or nuclear option.

“I believe that Majority Leader Reid wanted reform, but he also had to count votes, and he’s really the ultimate vote-counter. In the end, the votes were just not there. We came very close, and I believe we did move forward,” Udall said. “We got a compromise in the end that made progress, but still doesn’t go far enough.”

Udall contrasted the recent filibuster of Caitlin Halligan to be a D.C. Circuit Court judge with the talking filibuster launched by Sen. Rand Paul, R-Ky., over U.S. policy regarding the use of drones for targeted killings. He praised Paul for conducting business in the open.

In another sign that using such a maneuver would set off a procedural war, former Senate Parliamentarian Alan S. Frumin reiterated Thursday that it was the position of his office until he retired that the Senate was a continuing body and there was no special reason why a simple-majority rules change could occur at the start of a new Congress.

Frumin cautioned Thursday against a move to “bring down the nuclear hammer.” Frumin, who served as parliamentarian under both Democrats and Republicans, also warned the GOP against causing so many blockades that Reid feels he has no option but to change the chamber’s rules. Frumin said the GOP may regret causing Reid so much frustration because once the rules are changed, the bell cannot be unrung.

Frumin participated in a panel discussion that followed Udall’s speech at the Bipartisan Policy Center.