The word “historic” is often tossed around in Washington, but this change ends a tradition dating to the earliest days of the republic. For the nation’s first 118 years, there were no limits on debate in the Senate. After 1917, cutting off debate, or reaching “cloture,” required a two-thirds majority. In 1975, that threshold was reduced to 60 of 100 votes. Even that lower minimum required lawmakers to cooperate with each other.

“Cloture has fostered more bipartisanship in the Senate,” Donald Ritchie, the Senate historian, told me Thursday after Reid detonated his nuclear device. “The majority leader of the Senate is expected to try to work out some kind of a bipartisan deal to get enough votes to get cloture. Because the House is run by majority rule, it is seen as a sign of weakness if the majority leadership of the House has to get votes from the minority side.”

Now the Senate will be just as dysfunctional.

Reid was right that Republican obstruction has been intolerable; half of the 168 filibusters of executive and judicial nominations in the nation’s history, he noted, have come during the Obama presidency.

But Reid’s remedy — calling a simple-majority vote to undo more than two centuries of custom — has created a situation in which the minority leader, Mitch McConnell (Ky.), is expected to use the minority’s remaining powers to gum up the works, and to get revenge when Republicans regain the majority.