Debt ceiling drama heads down to the wire in Senate

With just days until the deadline for the nation to default, the Senate now is racing against the clock to pass a bipartisan debt ceiling agreement and avoid what would be an economically catastrophic failure to pay the country's bills.

Debate began Thursday morning as the chamber's leaders urged swift passage of the Fiscal Responsibility Act, with critics voicing their concerns with the bill.

"Time is a luxury the Senate does not have if we want to prevent default," Majority Leader Chuck Schumer, D-N.Y., said in remarks from the floor. "June 5 is less than four days away. At this point, any needless delay or any last minute hold-ups would be an unnecessary and even dangerous risk."

As the Senate deliberated into Thursday evening, Schumer was working with lawmakers who wanted to offer amendments to give assurances in exchange for limiting time for debate and votes.

Later Thursday, Schumer announced that voting would soon begin -- with passage expected within hours, either before or around midnight, after 11 successive rounds of voting on 11 different amendments. None of those looked set to pass but allowed various senators to register their differences with the debt agreement.

"By passing this bill we will avoid default tonight," Schumer said. "America can breathe a sigh of relief."

Here's how it happened.

No room for typical Senate delay

As the drama has played out, there has been almost no room for delay if the bill is to get to President Joe Biden's desk by Monday, the day Treasury Secretary Janet Yellen warned the U.S. could run out of money to be able to pay all its bills on time and in full.

In addition to the deadline, it has potentially helped that that's also supposed to be the start of a three-day weekend for senators -- and getting out of Washington is a time-honored motivator for faster action.

Leadership aides previously said a vote could happen as early as Thursday night but that required cooperation from the entire chamber.

Schumer: No changes, 'plain and simple'

Initially threatening to hold up the process was a possible filibuster or time-consuming debate and votes on amendments being sought by various lawmakers, mainly Republicans, but some Democrats too.

"We'll be here till Tuesday until I get commitments that we're going to rectify some of these problems," Sen. Lindsey Graham, R-S.C., warned at one point on Thursday.

He and other defense hawks spoke out on their frustration with the level of military spending in the bill, but any changes to the bill would force it to be sent back to the House for approval -- which would only drive them closer to the default deadline.

"We are going to do everything we can to move the bill quickly," Schumer told ABC News on Wednesday. "We cannot send anything back to the House. Plain and simple."

"We must avoid default, we must," he added then.

Minority Leader Mitch McConnell, R-Ky., had a similar "time is of the essence" message for his own conference.

"I can tell you what I hope happens -- is that those who have amendments, if given votes, will yield back time so that we can finish this Thursday or Friday and soothe the country and soothe the markets," McConnell said Wednesday.

How Senate passage timeline got set before the weekend

Chamber leaders scrambled behind the scenes to secure an agreement to have lawmakers voting on amendments and final passage by Thursday night.

While it was possible that 10 to 12 amendments could be voted on, lawmakers and aides said, ultimately 11 amendments were set for votes.

On Wednesday, Minority Whip John Thune, R-S.D., told ABC News that he thought it would be possible to get it all done by Friday.

Thune said that if Republicans got votes on roughly half a dozen amendments, even GOP opposition wouldn't block swift passage of the deal.

Despite concerns from some senators on defense and other issues, there appears to have been general agreement on the bottom line: that if the bill changed by even a single letter, it would have to return to the House and at that point -- both it and the country would face an uncertain fate.