Senate Republicans and Democrats closed in on a last-minute compromise Thursday on legislation opening the way to legal status and eventual citizenship for many of the 11 million immigrants living in the United States illegally.
Sen. John McCain, R-Arizona, said he had been assured President Bush supports the measure, and would publicly say so later in the day.
As outlined, the measure would provide for enhanced border security, regulate the future flow of immigrants into the United States and offer legalized status to the millions of men, women and children in the country unlawfully.
"We've had a huge breakthrough" overnight, said Majority Leader Bill Frist, R-Tennessee.
Sen. Harry Reid of Nevada, the Democratic leader, agreed, but cautioned that the agreement had not yet been sealed.
Even so, the presence of both leaders at a celebratory news conference underlined the expectation that the Senate could pass the most sweeping immigration bill in two decades, and act before leaving on a long vacation at the end of the week.
The developments marked a turnaround from Wednesday, when it appeared negotiations had faltered. The key sticking point involved the 11 million illegal immigrants in the country, and the struggle to provide them an opportunity to gain legal status without exposing lawmakers to the political charge that they were advocating amnesty for lawbreakers.
While final details were not available, in general, the compromise would require illegal immigrants who have been in the United States between two years and five years to return to their home country briefly, then re-enter as temporary workers. They could then begin a process of seeking citizenship.
Illegal immigrants here longer than five years would not be required to return home; those in the country less than two years would be required to leave without assurances of returning, and take their place in line with others seeking entry papers.
Not everyone was satisfied. A spokesman for Sen. John Cornyn said the Texas Republican was opposed to the measure. There was no immediate reaction from GOP Sens. Jon Kyl of Arizona or Jeff Sessions of Alabama, two other prominent critics of earlier proposals dealing with illegal immigrants.
Beyond the illegal immigrants, there were other thorny issues to be clarified. Senate leaders had yet to publicly unveil draft legislation to make sure that only legal workers were hired in the future, for example.