That's it. The Senate finally went nuclear.

A majority of Democrats voted on Thursday to modify the Senate's rules on filibusters for the first time since 1975. From now on, judicial nominees to federal courts can be confirmed by a simple majority vote. So can the president's executive-branch nominations.

It's not a complete repeal of the filibuster: Supreme Court nominees can still be blocked by 41 senators, as can all legislation. But even this smaller rule change — a move known as the "nuclear option" — is a big break with precedent.

In all, 52 Democrats voted to change the filibuster rules, while all 45 Republicans and 3 Democrats opposed the move. (West Virginia's Joe Manchin, Michigan's Carl Levin, and Arkansas's Mark Pryor were the three dissenting Democrats.)

Reid pushed to change the rules after Republicans once again blocked the nomination of Patricia Millett to the U.S. Appeals Court for the Washington, D.C., Circuit. The Senate voted 57 to 43 to reconsider a vote on her nomination, but that wasn't enough to overcome a filibuster.

Once that happened, Reid went nuclear. He raised a point of order calling for a majority vote to move forward. The Senate parliamentarian ruled Reid's motion out of order. Reid then appealed the ruling, and 52 Democrats supported him. That vote, in effect, altered the Senate rules: A simple majority is now sufficient to cut off filibusters on nominations.

That maneuver, in itself, is a huge deal. In the past, a two-thirds majority has been required to change the Senate's rules in the middle of the session. The fact that Reid changed the rules with a simple majority sets a new precedent — that's why it's known as the "nuclear option."

Reid had threatened this maneuver before after growing frustrated by GOP filibusters, but each time, he backed down after Republicans agreed to let some nominations through. This time, there was no deal.

On the floor earlier on Thursday, Reid complained that Republicans have repeatedly blocked President Obama's judicial nominees and executive-branch appointments over the past five years. That includes Obama's three nominees to the important D.C. Circuit Court of Appeals — Millett, Nina Pillard and Robert Wilkins — as well as executive-branch nominees like former Congressman Mel Watt, who was nominated to head the Federal Housing Finance Agency.

"In July, after obstructing dozens of executive nominees for months, and some for years, Republicans once again promised that they would end their unprecedented obstruction," Reid said. "One look at the Senate’s Executive Calendar shows nothing has changed since July." He pointed out that there are 75 executive-branch nominations currently in limbo, having waited an average of 140 days.

Republicans, for their part, warned that Democrats will come to regret changing the Senate's rules in this fashion — particularly if the GOP ends up retaking the chamber in the 2014 elections. “You’ll regret this, and you may regret this a lot sooner than you think,” said Senate Minority Leader Mitch McConnell (R-Ky.).

Back in June, McConnell warned that if Reid changed the filibuster rules for executive-branch nominees, the filibuster would eventually die altogether. "There is not a doubt in my mind," he said, "that if the majority breaks the rules of the Senate to change the rules of the Senate with regard to nominations, the next majority will do it for everything."

Further reading: