FILIBUSTER REFORM PACKAGE UNVEILED IN THE SENATE…. With the new Senate officially being sworn in this afternoon, reform-minded members were finally able to present their proposed changes to how the chamber would operate.

The package of changes was unveiled today by Sens. Tom Udall (D-N.M.), Jeff Merkley (D-Ore.), and Tom Harkin (D-Iowa), and while most of the proposals were well known, these final details matter, and will serve as the starting point for institutional talks over the next couple of weeks.

As promised, Udall proposes ending secret holds and the right of the minority to filibuster the start of debate, and demanding the “talking” filibuster.

But, according to documents provided by Udall’s office in advance of his floor speech, it also includes a proposal that guarantees both parties the right to amend legislation — limiting the majority leader’s power to “fill the amendment tree” and block extended debate.

“This provision addresses comments of Republicans at last year’s Rules Committee hearings,” the summary reads. “Each time Democrats raised concerns about filibusters on motions to proceed, Republicans responded that it was their only recourse because the Majority Leader fills the amendment tree and prevents them from offering amendments. Our resolution provides a simple solution — it guarantees the minority the right to offer germane amendments.”

The unexpected provision also seems like a reasonable idea — if adopted, by the majority leader and the minority leader would be able to present three germane amendments to bills, curtailing the “filling the tree” approach that limits the minority’s ability to alter legislation.

Also of note, under the status quo, after a filibuster is defeated, the Senate has to wait 30 hours before it can do anything else. Under the Udall/Harkin/Merkley plan, the chamber would have two hours of debate after cloture is complete.

Greg Sargent posted the complete text of the five-point reform plan.

Keep in mind, those looking forward to big decisions on this today will be disappointed. The reform plan was introduced today, but members will now continue to debate how to proceed. Because rules have to be agreed upon at the start of the session, the Senate will recess today and return on Jan. 24 — and it will technically still be the first legislative day.

This gives senators quite a bit of time to try to rally support (or opposition) to institutional reforms. As for what kind of changes, if any, are likely, the Republican leadership’s hostility to changes appears to be hardening, but we’ll know more soon enough.

Steve Benen

Follow Steve on Twitter @stevebenen. Steve Benen is a producer at MSNBC's The Rachel Maddow Show. He was the principal contributor to the Washington Monthly's Political Animal blog from August 2008 until January 2012.