Attorney General Eric Holder finally sent his answers from a November hearing to Senate Republicans Monday, on what was presumed to be the eve of an expected showdown between Holder and the GOP lawmakers over plans to close Guantanamo Bay prison and put detainees on trial in civilian courts.

But while Holder, his aides and Republican lawmakers were separately intently planning for the hearing before the Senate Judiciary Committee, Senate Democrats were fretting about potentially missing the White House party to celebrate passage of a health care bill, aides acknowledged. Judiciary Chairman Sen. Patrick Leahy, D-Vermont, postponed the hearing late Monday to the consternation of both the Justice Department and the GOP.

Holder is out of town on travel the rest of this week, and Congress is out the following week, so no new hearing date is scheduled. The last-minute delivery of Justice Department responses to questions asked by the Republicans more than four months ago appeared to fuel an already agitated group of senators from the staunchly partisan Senate judiciary panel.

GOP staff members were scrambling to go through the documents in advance of what they expected would be Holder's scheduled 9:30 a.m. appearance before the committee. If the hearing had taken place, it would have marked Holder's first appearance before the Senate panel since November, a few days after he proclaimed his decision to try the alleged 9/11 conspirators in New York City.

Holder told the committee he had the full backing of New York political leaders, and insisted a civilian trial near the site of the 9/11 attacks was the right thing to do.

Since then, however, the attempted Christmas Day airliner bombing and collapse of New York support for a New York City trial have left Holder and the Obama administration struggling for a solution to detainee issues. White House sources have indicated the president, not Holder, will make the final decision on where to try accused 9/11-mastermind Khalid Sheik Mohammed, and it will most likely be in a military court.

Republican sources say the minority side was prepared to bombard Holder with what they see as inconsistencies and errors. They said Justice Department officials acknowledged in Monday's last-minute dump of documents that they can not provide the details to back their assertion that 300 terrorists have been successfully tried in civilian courts.

Republicans also prepared to attack Holder on other fronts, including his failure to disclose seven legal briefs he had written in support of positions in federal court cases.

Holder last week told a House budget committee he expects a decision on the Khaled Sheik Mohammad trial to be made within "a few weeks". He had not been expected to provide any new information on the status of the decision. With the hearing postponed for weeks, the decision on the 9/11 trial could precede Holder's delayed appearance.