Faced with the prospect of having their two top leaders pinned down in their states fighting re-election battles next year, Senate Democrats are expected to rely on a mix of rising stars, mid-level lieutenants and old bulls to fill key fundraising and legislative roles.

Minority Leader Tom Daschle (D-S.D.) and Minority Whip Harry Reid (D-Nev.) are waiting to see if they will face challenges from former Rep. John Thune (R) and Rep. Jim Gibbons (R), respectively.

GOP Senators said they see both the near-term benefit of tying down the chamber’s opposition leaders with politics at home as well as the long-term potential for defeating a pair of incumbent Democrats in states President Bush carried in 2000.

“It is not just boxing him in, it is the reality that that seat could be Republican,” Sen. Larry Craig (R-Idaho) said of the strong possibility that Thune will seek to take on Daschle, noting that Gibbons poses a similarly difficult challenge to Reid. “This guy is clearly competent in all regards.”

As Nos. 1 and 2 in the Caucus, Daschle and Reid play key roles in the Democrats’ campaign and legislative operations. Both are prodigious fundraisers, although the bulk of that responsibility rests on Daschle’s shoulders.

While Daschle gravitates to the Senate floor during flareups in legislative activity, Reid handles the minute-to-minute and hour-to-hour floor duties as the chief emissary to Republicans.

“It ties them down more than they would otherwise be able to do,” Democratic Senatorial Campaign Committee Chairman Jon Corzine (N.J.) acknowledged of the potential strong challenges.

In the scenario in which both Gibbons and Thune run, Democrats such as Sens. Robert Byrd (W.Va.), Tom Carper (Del.), Hillary Rodham Clinton (N.Y.), Daniel Inouye (Hawaii), Edward Kennedy (Mass.), Mark Pryor (Ark.) and Debbie Stabenow (Mich.) are expected to step up and join Sens. Byron Dorgan (N.D.), Dick Durbin (Ill.) and Corzine in assuming more prominent roles in the Caucus.

“If something like that should happen, I am certain men and women in the Caucus would get together to pitch in,” Inouye said. “I think you can count on every Democrat to do that.”

The duties that would need to be picked up include the strictly mundane, such as running the floor. On a recent Tuesday evening, for example, Daschle rushed out the Capitol doors just after 6 p.m. while the Senate was still at least 90 minutes away from wrapping up debate for the night on a series of noncontroversial items. He summed up his early departure in one word: “Fundraiser.”

That same night Reid also had politics to tend to, so it was left to Durbin, the Assistant Floor Leader, to handle debate for the Democrats.

Under a still-emerging game plan, Senators such as Durbin, Byrd and Inouye would likely have clearly defined roles in helping to manage the floor. Others, such as Clinton and Kennedy, would likely be tapped for dual duties, both on the Senate floor and the fundraising circuit.

In recent months, Clinton has raised her political profile by serving as head of the Democratic Steering and Coordination Committee and taking a lead in speaking out against Bush’s legislative agenda. As she crisscrosses the nation to promote her new book, the New York Senator is also aggressively raising money for her colleagues and the DSCC.

“I am just going to keep doing what I am doing, which is chairing the Steering Committee, helping leadership in any way that I can and raising money,” she said. “Just whatever I need to do.”

Kennedy, meanwhile, headlined a recent DSCC fundraiser in Chicago.

The new emphasis on fundraising by the likes of Clinton and Corzine will be critical because of the inordinate amount of donor work that Daschle has traditionally done for the DSCC, which he already scaled back somewhat this year as he focuses on his own re-election. Both Reid and Daschle posted cash-on-hand totals around $3 million in their re-election committees as of June 30, but each dramatically cut fundraising activities for their leadership political action committees.

DASHPAC raised just $334,425 in the first six months of the year, down nearly 50 percent from the first half of 2002 and down sharply from 2001, when Daschle took in $1.1 million in the first six months for his leadership committee. Reid raised just $56,000 for his Searchlight Leadership Fund, down from the $264,480 he raised in the first half of 2002, according to filings with the Federal Election Commission.

“Yes, their time will be limited,” Sen. Mary Landrieu (D-La.) said of Daschle and Reid. “But we have a deep bench. There are other Democratic Senators that can step forward. There will be committee [ranking members] that step up, there will be others that step up.”

Some younger Senators are also expected to take on a greater share of duties, including Carper and Pryor, who are considered “workhorses” willing to help fill floor time or dial for dollars for the DSCC, said a Senate Democratic chief of staff.

Dorgan, chairman of the Democratic Policy Committee, is also running for re-election in 2004 but Republicans so far have failed to recruit a top-tier candidate to challenge him.

Durbin sailed to victory in 2002 and just last week raised his national profile by criticizing the White House for allegedly misleading the public about Saddam Hussein’s efforts to procure uranium in Africa to build a nuclear weapon.

Some observers are suggesting next year could become a dress rehearsal for Senators interested in a promotion should either leader lose. It will also be a chance for the ambitious to audition with an eye to the day either retires from leadership.

“It could be make-or-break time for those within the Caucus with ambitions to move up the leadership ladder,” said a senior Democratic aide.

Still, several Democrats acknowledged there has been no detailed planning to prepare for such a scenario, a fact that has caused some to express concern. Specifically, there is apprehension that the absence of both Daschle and Reid — either from their need to be on the campaign trail next year or from a defeat at the polls for either Senator — could result in an already politically fractured Caucus flying apart.

“They have the ability and capacity to hold everyone together in spite of the differences,” said one Senator, who demanded anonymity.

“All sides trust, as well as like, Daschle and Reid, and consequently you lose that capacity,” the Senator added. “Somebody would have to step in to replace them and the question is, who could?”

GOP leaders hope to dilute Reid’s and Daschle’s effectiveness in the coming months, suggesting the two leaders must face the same voters who helped elect Bush in 2000. Calling their leadership posts a “two-edged sword,” Sen. Bob Bennett (R-Utah) said Reid and Daschle may have to modify their rhetoric or their votes because of the GOP-leaning nature of both states.

Some Republicans said they would highlight the fact that both of these Democratic leaders worked to stop Bush’s legislative agenda at every turn, regardless of what they do in the next 15 months.

“It ain’t what they are going to say, it is what they have already said,” said Gibbons, who plans to announce his future political plans in the latter half of August. “A record is a record, whether it is yesterday’s or today’s.”

But Corzine said vilifying Daschle and Reid could backfire on Republicans by energizing a Democratic base eager to rush to the Senators’ defense.

“When your friends are under fire, it encourages them,” Corzine said of Democratic voters.

While nine Democrats continue the scramble to become their party’s presidential nominee, Senate Democrats said they will continue to look to Daschle for direction — even if he is locked in a difficult battle at home — until a standard-bearer is selected.

“Tom Daschle is our leader and that is the person who speaks. Whether he is campaigning in South Dakota or here, he is the person in charge,” said Sen. Chris Dodd (D-Conn.).