With both sides drawing lines in the sand, Senate Democrats and Republicans braced Tuesday for a filibuster battle over the judicial nomination of Miguel Estrada.

Minority Leader Thomas Daschle (D-S.D.) declared he had “more than enough” votes to block consideration of Estrada’s bid to the prestigious U.S. Court of Appeals for the D.C. Circuit, while Republicans countered by refusing to file a cloture motion and threatening to draw out the debate as long as possible.

The Estrada debate has potentially serious long-term implications for the struggle to win the Hispanic vote and for the way Supreme Court vacancies will be filled in the future. But it also provides an immediate test for the leadership of both parties and ramifications for both next week’s planned Congressional recess and the early fundraising schedule for 2004 candidates hoping to fill their campaign war chests before the next filings at the end of June.

After a week of public wavering on whether they would go to the admittedly drastic length of filibustering Estrada — no lower-court nominee has ever been defeated on the floor through the procedural maneuver — Daschle and his leadership team made the decision at a Tuesday morning meeting in his office, a call that was backed up by the overwhelming majority of the Caucus at a luncheon meeting.

Daschle said the decision also signaled the Democrats’ continued frustration with the Bush White House over its alleged refusal to seek consultation on issues ranging from judicial nominations to the war on terror and other international flashpoints. Democrats have maintained that Estrada stonewalled the Judiciary Committee in his responses to Democratic questions and that he and the Bush administration have refused to turn over memoranda he wrote while working in the solicitor general’s office from 1992 through 1997.

“If this precedent succeeds, we can expect every single nominee to come forward with the same stonewalling attitude,” Daschle said.

Majority Leader Bill Frist (R-Tenn.) countered with a threat to keep the chamber open for late-night debates this week and possibly terminating the planned Presidents Day recess next week. “We’ll stay as late as they would like tonight and tomorrow night,” Frist said Wednesday. “But my expectation is that by the end of this week, and before our recess, and possibly into our recess, we expect what all American people expect and deserve: an up-or-down vote on this outstanding candidate.”

While neither side would officially declare the current floor action a filibuster, the effect was the same. Democrats will not allow a unanimous consent motion to bring Estrada’s nomination to a vote on the floor, while Republicans are refusing to file cloture to force a vote. For the time being, Democrats can maintain their unofficial filibuster as long as they have one Senator on the floor to object to any Republican calls for unanimous consent on Estrada.

Frist and his fellow Republicans contended that a move to file cloture would set a standard requiring judicial nominees to gain 60 votes, instead of just 51. The last judicial nominee effectively defeated by filibuster was Supreme Court Justice Abe Fortas, whose bid to become chief justice failed in 1968.

But Frist’s handling of the Estrada issue is shaping up as one of the first true tests of his leadership skills within the GOP Conference, as a group of Senate Republicans are pushing to take the hardest line possible on the nomination fight. He pointedly left open the possibility of filing a cloture motion at some point. “There’s been no decision made in terms of whether to file cloture or not. … It may be that at some point we come to that. I would like to think we don’t have to go to that, that we’ll have an up-or-down vote with or without it,” he said.

Sen. Kay Bailey Hutchison (Texas), vice chairwoman of the Republican Conference, echoed Frist, adding, “At some point, if all else fails, if we have to lose Estrada or file cloture, we’ll file cloture.”

But Republican Conference Chairman Rick Santorum (Pa.) was unequivocal at a morning press conference and again after the weekly party luncheons that there would be no cloture vote, and that Estrada’s magic number for confirmation remained a simple majority: “Fifty-one votes will be the bar that Miguel Estrada will have to climb, not 60.

“Most of our guys feel good about being here next week.”

One GOP aide described Santorum as the head of a “core group” that is pushing for Frist to take a very hard line, seeking late-night procedural votes this week and a cancellation of next week’s recess, whatever it takes to exert the maximum possible pressure on Democrats. Sens. Jon Kyl (Ariz.), chairman of the Republican Policy Committee and a Judiciary member, and Don Nickles (Okla.), the Budget chairman and former GOP Whip, are also pushing the hard line.

“There is overwhelming support in our caucus to stay here as long as necessary,” Nickles said Wednesday. “If it means cancelling next week, that means cancelling next week.”

Senior Democratic aides have been quick to note that they doubt Frist would resort to late-night tactics, considering it would take two Republicans (one to be on the floor, one to run the chamber) and just one Democrat to keep the floor open.

And next week’s recess is going to be critically important to both sides in terms of fundraising, aides note. With the mid-January recess cancelled because of the lingering fight over last year’s spending bills, a litany of out-of-town fundraising events have already been postponed once.

Another cancelled recess would mean more missed money events, and the Senate would not be slated to take another recess until the end of April.

Daschle’s leadership will face a test of its own. Only three Senate Democrats — John Breaux (La.), Ben Nelson (Neb.) and Zell Miller (Ga.) — have so far announced their support for Estrada’s confirmation, but many Democrats had been privately hesitant to endorse what one aide called a “full-fledged” filibuster.

Breaux said Wednesday that his Caucus was heeding too much advice from “base interest groups” such as People for the American Way and the NAACP. He said Estrada, who would be the first Hispanic on the D.C. appellate court, didn’t have an easily dissectible record and argued his party was providing Bush an opening to use the presidential bully pulpit to pound away at Democratic obstructionism.

If Democrats want to take on a conservative judicial nominee, there will be plenty of other chances, Breaux said, adding, “You ought to find the best target to make the case.”

But in the past week the overwhelming majority of Democrats became convinced that Estrada’s was the perfect case for a filibuster.

Liberal interest groups have bombarded Senate Democrats with phone calls, e-mail alerts and faxes urging a filibuster of Estrada — close to 30,000 each from People for the American Way, AFL-CIO and move-on.org.

One outside observer said Democrats were being swayed by the argument that they need to stand up to Bush on the basis of institutional integrity and that the White House had been trying to bully Democrats into submission on a wide variety of issues. The observer noted that on the same day Bush put forward a $674 billion tax-cut plan that far exceeded expectations, he also renominated Charles Pickering and Priscilla Owen, two GOP judicial nominees rejected last year by Judiciary.

Sen. Russ Feingold (D-Wis.) said that not filibustering Estrada would send Bush the signal that Democrats were going to lay down without a fight. “It sends the signal that the administration can get away with anything,” he said.