Sen. John Sununu, R-N.H., a leader in the talks with the White House, said no one disputes the importance of subpoena powers and other tools the government needs to pursue terrorist activities. "But we want to make sure they are balanced by basic protections for civil liberties."
Renewal of 16 provisions of the 2001 Patriot Act was held up late last year when Sununu and three other Republicans joined almost every Democrat in filibustering the legislation.
With the agreement, supporters were close to the 60 votes needed to overcome another filibuster attempt, and it appeared that Democrats would not stand in the way of legislation that provides the government critical legal and investigative powers in the fight against terrorism.
Democratic leader Sen. Harry Reid of Nevada issued a statement saying the agreement among Republicans "appears to be a step in the right direction."
The second-ranked Democrat, Dick Durbin of Illinois, joined the news conference with Sununu and other involved Republicans to say that, while he still wanted further clarification to protect libraries from searches for records, "I do believe on balance that this is a better version of the Patriot Act."
Judiciary Committee member Sen. Dianne Feinstein, D-Calif., also said the bill had been substantially improved by the changes and she would vote for it.
Any changes made would still have to be approved by the House, but Sen. Larry Craig, R-Idaho, another negotiator, said that with the Senate and the White House in concert, he thought the House would go along. He said he had consulted with House Judiciary Committee Chairman James Sensenbrenner, R-Wis. "There will be no additional negotiations," Craig said.
The changes, worked out over several weeks of talks, specifically with the office of White House counsel Harriet Miers, covered three main areas:
White House spokesman Scott McClellan said the agreement would "continue to build upon the civil liberties protections that are in place but do so in a way that doesn't compromise our national security priorities."
But Sen. Russell Feingold, D-Wis., a leader in opposing the act, said he would continue to fight it.
He said the deal did not provide meaningful judicial review of gag orders because such review can only take place after a year has passed and can only be successful if the recipient proves the government acted in bad faith.
The deal also does not ensure that when government agents break into homes to do "sneak-and-peek" searches that they tell the owners of those homes in most circumstances within seven days, as courts have said they should, Feingold added.
The law originally was passed within days of the attacks of Sept. 11, 2001, and the administration says it has been an important weapon in the government's arsenal for tracking suspected terrorists.
Renewal of the law was blocked last year when critics said its provisions shortchanged civil liberties, particularly in the cases of individuals who were not suspected of terrorist activities themselves, but might have had innocent dealings with suspects.
Also at issue was concern over the government's ability to demand information from libraries.
As a result of the deadlock, lawmakers had to approve two temporary extensions of the old law. The current extension expires March 10.
Republicans said that with the changes, the chance would be remote that any library would have to turn over information.
But Democrats said the same provision made explicit that some libraries could be forced to turn over information, adding that existing law is vague on the subject.
Other than Sununu, the Republicans who had defied the president's wishes on the Patriot Act last December were Craig, Lisa Murkowski of Alaska and Chuck Hagel of Nebraska.