Democrats will make an attempt to reform the Senate's filibuster rules, Sen. Sherrod Brown (D-Ohio) said Wednesday.

Brown joined other members of his party who have been signaling, in the closing days of the lame-duck Congress, that their party is likely to seek changes to longstanding Senate rules that require 60 votes (instead of a simple majority of 51) to advance most pieces of legislation in the chamber.

"I think you're going to see attempts to do that," Brown said Wednesday morning on MSNBC, referring to the prospects for filibuster reform.

The filibuster, or at least the implied threat of one, has been used to great effect in the past two years by Senate Republicans to slow down or flat-out block pieces of legislation favored by Democrats.

Sen. Tom Harkin (D-Iowa), a high-profile congressional liberal, is expected to address the need for filibuster reform in a speech at the National Press Club on Wednesday morning.

Sen. Tom Udall (D-N.M.) has also been exploring options for filibuster reform, and suggested that the Senate might exercise the "constitutional option" and change Senate rules with a simple majority of votes on the first day of its next session. Since the Constitution gives the House and Senate the power to set their own rules, Udall's proposal would seem to bypass the higher threshold required to change Senate rules.

"We can fix it on the first day, because with 51 senators and utilizing the constitutional option, we can move to a situation where we change the rules," Udall said last night on MSNBC. "Obviously, I may be in the minority at some point, so I want minority rights protected. But we can make the Senate work more efficiently. And that's what we're working on right now."

Even though Democrats had controlled 60 seats on their own for some time during this past session of Congress, they couldn't always get all of their members onboard with some of their largest agenda items.

Sen. Scott Brown's (R-Mass.) victory in a special election in January of 2009 gave Republicans a 41st vote, and with it the ability to sustain a filibuster against any piece of legislation, as long as all members of the GOP held together.

Republicans' willingness to filibuster legislation has led to several options for reform that Senate Democrats have studied. Sen. Charles Schumer (D-N.Y.) has held meetings on the idea, and the options for reform include ideas ranging from requiring senators to speak continuously during an actual filibuster to lowering the threshold of votes that can end a filibuster.

"We still want to protect the rights of the minority in the Senate," Sherrod Brown said, noting that his own party's Southern members had inappropriately used the filibuster to try to block civil-rights bills in the 1950s and '60s.

Still, it could be difficult to secure any agreement to change the rules. Under Senate protocol, 67 senators would have to agree to change filibuster rules, meaning that at least nine GOP senators would have to vote for a change. That could be especially difficult, considering Republicans are still in the minority in the Senate in the next two years.

Democrats' window to achieve filibuster reform is rapidly closing, too. They're rushing to finish tax cuts, an immigration bill, a nuclear arms treaty and a repeal of the military's "Don't ask, don't tell" policy before the new Congress is sworn in Jan. 5. That next Congress will include many more Republicans in the Senate, who are probably even more disinclined to support a change in the filibuster rules.

Brown lamented that his party didn't seek filibuster reform at an earlier point in the last two years.

"Maybe we could have" done filibuster reform earlier, he said. "We were working on other things."

Updated 8:16 a.m.