Durbin said all but a handful of the Senate's 44 Democrats and one independent supported the bill as currently drafted. In the Senate, 60 votes are needed to ensure passage and override a possible filibuster by opponents.
"If they can produce 20-plus votes, we can get a bill this week," Durbin said of the Republicans.
Even before Democrats filed the motion to end debate, Republicans accused them of being obstructionist and trying to scuttle the bill by blocking debate over amendments. And the atmosphere on and off the Senate floor grew more and more heated during the day, as Republicans realized Democrats were digging in their heels.
"I feel like there are those who are trying to jam this version of the bill down our throats ... trying to deny those of us who have different ideas from presenting those ideas," said Sen. John Cornyn (R-Texas), who opposes any citizenship provision for workers currently in the United States illegally.
Democrats were unapologetic, with Reid noting pointedly that Republicans had repeatedly barred the minority from offering amendments on other legislation.
"As my mother would say, they're getting a taste of their own medicine," Reid said.
Members and staff were meeting into the evening in an effort to agree on a compromise that might permit votes on less controversial amendments.
Republicans were also debating whether to file a countermotion to the Democrats that would force a vote on a competing bill -- currently on the sidelines -- that would enhance border security but does not include a guest-worker program or legalization.
Both sides said it was too soon to predict the demise of the immigration reform effort.
"We have time on our side. As we get closer to recess, cooler heads will prevail," said Sen. Ken Salazar (D-Colo.).
Despite holding a string of meetings in recent days, Republicans have reported little progress toward bridging their differences, however. Senators said discussion at the weekly Republican strategy lunch was lively, loud, and in the end, inconclusive.
"We're 100 senators and I think if you polled us you would find 100 different ways of dealing with illegals," said Sen. John Ensign (R-Nev.).
"We're still looking for the magic formula," said Sen. Mel Martinez (R-Fla.).
