UPDATE: Senate Democrats voted to invoke the so-called nuclear option just after noon on Thursday, changing the rules so that only a simple majority vote is required for confirmation of all executive and most judicial nominees. After the vote, Senate Minority Leader Mitch McConnell (R-Ky.) asked for an appeal vote.
The Senate began debate over reforming the filibuster at 10:40 Thursday morning and Democrats stood in lockstep behind Reid. "You will regret this," warned McConnell. "You may regret it a lot sooner than you think."
WASHINGTON -- The Senate could go nuclear as soon as Thursday morning, according to three Democratic Senate sources close to the decision.
Majority Leader Harry Reid (D-Nev.) is prepared to change Senate filibuster rules by invoking the "nuclear option," or by using arcane Senate procedures to change the rules with just 51 votes instead of the standard two-thirds majority vote. Under Reid's new rules, only a simple majority would be required for all executive and judicial nominees other than those to the Supreme Court. Reid is meeting Thursday afternoon with progressive advocates of rules reform.
For years, as reformers in the Senate pushed for a rules change, they encountered resistance from veteran senators such as Judiciary Committee Chairman Pat Leahy (D-Vt.), Sen. Dianne Feinstein (D-Calif.) and even Reid himself, who all defended Senate tradition and also warned about turnabout once the GOP inevitably gained control of the chamber.
But the Senate's inability to function, and the GOP's steadfast opposition to appointing any new judges to the powerful D.C. Circuit Court, has worn down Democratic opposition to a rules change, leaving Sen. Carl Levin (D-Mich.) as the lone outspoken opponent.
Feinstein and Sen. Barbara Boxer (D-Calif.) both flipped positions on Tuesday.
Asked by HuffPost at a local event Thursday if he supports what Reid is doing, Vice President Joe Biden said, "Yes, I do." The vice president is authorized by the Constitution to cast tie-breaking votes.
It's still not clear if Reid has the 51 votes to make the change, but it certainly looks close. There are 55 Democrats in total, which means Reid can lose up to four. HuffPost tracked down a number of Democrats on Tuesday to see who remains opposed to making the change, and only one, Levin, definitively said no. A couple of others, Sens. Max Baucus (D-Mont.) and Claire McCaskill (D-Mo.), avoided the question.
Most recently, Republicans blocked all three of Obama's nominees to the D.C. Circuit Court of Appeals, plus another one earlier this year.
Filling vacancies on that court is a huge priority for the president, given the court's broad power to review federal regulations relating to air and water rules, nuclear plant safety, insider trading and, notably, the Affordable Care Act. The court has 11 seats; four are filled by GOP-appointed nominees and four are filled by Democrat-appointed nominees. Former President George W. Bush had four nominees confirmed to the panel during his tenure. By contrast, Obama has only had one.
This is a developing story.