effectively transformed the Senate from a majority-rule body into one that effectively operates only by a 60-40 supermajority.

Today is the day when the Senate, as we've explained, has the opportunity to change the rules with a 51-vote majority. And what has Republicans really worried is that, thanks to their massive abuse of the filibuster in the just-ended lame-duck session, Democrats now are unanimous about wanting to change the rules.

So there was Mitch McConnell whining in the WaPo yesterday about the truck rolling toward their favorite tactic, calling it a "power grab" (as we knew they would):

All of this is newly relevant because some on the left are agitating once again for partisan rule changes aimed at empowering the majority at the expense of the minority. They have peddled the well-worn myth that changes are needed as a way of overcoming partisanship on the part of Republicans. Their evidence: a historically high number of so-called cloture petitions by the Democratic majority to cut off debate. Republicans forced these petitions, Democrats say, by blocking or slow-walking bills.

What these critics routinely fail to mention (and too many reporters fail to report) is the precipitating action: the Democratic majority's repeated use of a once-rare procedural gimmick that has kept Republicans from amending bills that are brought to the floor. This practice, known as "filling the amendment tree," leads to a question that answers itself: Why would Republicans vote for action on a bill that, we've been promised, we'll be blocked from contributing to in any way? If the majority wants more cooperation, it could start by allowing differing views to be heard.

This is, of course, a load of hooey: Democrats' use of "filling the amendment tree" has largely been itself precipitated by the Republicans' abuse of "poison pill" amendments -- and was, moreover, a practice they themselves used heavily when they were in power. As Harry Reid put it: "This isn't a new method that I dreamed up. Anytime there is an election there is not a leader who is dumb enough to put a bill on the floor that is subject to amendments." Here's a guarantee: If Mitch McConnell is ever Majority Leader again (heaven forbid), he will be the first to implement the practice, since it's one that he himself honed over the years prior to 2007.

Moreover, if you wanted evidence of Republican abuse of the rules to prevent the Senate from proceeding as the Founders designed it to, just look at the just-finished lame-duck session. Certainly it's fresh in Democrats' minds.

It seems Lamar Alexander is worried too, because he's appealing to the Senate's inner Beltway Villager:

Senator Lamar Alexander derided Democrats’ efforts to rein in the use of filibusters in the Senate as a “brazen power grab” and warned of “guaranteed” retribution when Republicans return to the majority.

Democrats are expected to introduce rules Wednesday that would require lawmakers to be on the floor to filibuster legislation and lower to 51 the number of votes required to adopt the new rules.

In a speech Tuesday at the Heritage Foundation, a conservative policy organization in Washington, Mr. Alexander, a Republican from Tennessee, said the changes would allow the shrunken Democratic majority to ram through legislation with little or no input from across the aisle–a tactic Senator Harry Reid himself opposed when Democrats were in the minority.

Yep, conservatives have been awfully certain that Democrats will lack the spine to pull this off. They may well be right. But we all know that this is long overdue.

And if you need a reminder of why, just read your Constitution.