It was D-Day in the Senate Wednesday as the Democrats moved in to take command for the first time since 1994.

With Vermont Sen. James Jeffords' departure from the GOP finally official, Democrats are taking control of the full Senate by a 50-49 margin, plus Jeffords, and of each of its committees. But Republicans weren't giving up that easily.

"I want everybody to understand that while we may not be in the majority, we are going to make sure that the American people's agenda is considered as we see it," the outgoing majority leader, Sen. Trent Lott, R-Miss., said Tuesday.

The morning of his first day at the helm, new Senate Majority Leader Tom Daschle stressed bipartisanship, but cautioned he would also use his party's new muscle to stop President Bush on areas where they disagree.

"Our role is to try to find a way to work together, to agree where we can, to compromise where we find the real possibility of doing so. But obviously on occasion we will see it as our role to stop something that we don't think is appropriate policy," he said on ABC's Good Morning America.

Daschle, D-S.D., appeared on morning news shows on five television networks just hours before he was to be recognized on the Senate floor as majority leader for the first time. "Both sides have to come to the middle. We can't just lob bombs," he said on NBC's Today Show.

Daschle cited education, patients' rights and energy as areas where he said the two parties can reach compromise.

But after his television appearances, he conceded in a brief interview that it may be difficult for the Senate to be productive with the narrow majority Democrats will have.

"That's what remains to be seen, what can the Senate produce under these circumstances," he said.

Republican leaders were also talking about compromise, but showing a combative side as well.

"We should have a war of ideas, and we should have a full campaign for the Senate in 2002," said Lott, whose five years as majority leader saw some conservatives accuse him of being too accommodating to Democrats.

Before Jeffords' departure from the GOP, Republicans had used the tie-breaking vote of Vice President Dick Cheney to control the evenly divided Senate since January. This is the first time Senate control has shifted during a session, other than after the 17 days last January when Vice President Al Gore temporarily gave Democrats the upper hand.

As of Tuesday evening, the plan was for a Republican to be in the chair at the start of Wednesday's session.

By voice vote, the Senate would quickly elect Sen. Robert Byrd, D-W.Va., the senior Democratic senator, to replace Sen. Strom Thurmond, R-S.C., as president pro tempore, a largely ceremonial post that is third in line for presidential succession. Byrd would then recognize Daschle to speak as majority leader, kicking off the Democrats' rule.

Democrats ultimately will have a one-seat majority on each committee, but the Senate will have to approve a resolution to make that official. That resolution is the subject of GOP talks with Daschle that were expected to resume Wednesday, with Republicans insisting that Democrats also promise timely votes on Bush's nominations.

Daschle predicted that Republicans would not use a filibuster, or a long procedural delay, to press their demand that Democrats let the Senate vote on Bush nominations, especially for judgeships.

Physical evidence of the Democratic takeover also were to emerge Wednesday. Workers were to shift Jeffords' desk a few feet over to the Democratic side of the aisle, some leadership and committee staffs were trading offices, and some signs were being replaced.

For the first time, Jeffords joined Senate Democrats Tuesday at their weekly lunch and received a standing ovation.

"I was a little bit numbed," Jeffords said afterward, adding he has "never had second thoughts" about ending his lifelong affiliation with the GOP.

At the White House, Bush met with senators of both parties to discuss the bipartisan education bill wending its way through the Senate. He preferred to cast his party's loss of Senate control in positive terms.

"There's going to be an opportunity for us to work on a variety of issues" with Democrats, he said.

Underlining his effort to reach out, Bush had dinner at the White House Tuesday evening with Sen. John McCain, R-Ariz., his one-time presidential rival and frequent nemesis. Daschle, who played host Tuesday to House Speaker Dennis Hastert, R-Ill., is scheduled as Bush's dinner guest Thursday.

The Associated Press contributed to this report.