Republicans recaptured control of the Senate last night, ending 17 months of Democratic rule and giving President Bush dominance over both houses of Congress and their legislative agendas.

Republican candidates knocked off at least two Democratic incumbents, in Georgia and Missouri, and held all but one of their own endangered seats, losing only in Arkansas, to produce either an outright GOP majority or a 50-50 tie that would be broken in the party's favor by Vice President Cheney.

The pivotal moment came early today when former representative Jim Talent (R) ousted Sen. Jean Carnahan (D), who was appointed two years ago after her husband, killed in a plane crash, was posthumously elected to the Senate. Carnahan went before supporters shortly after 2 a.m. Eastern time, and conceded defeat.

"It's been a very successful night for the Republican Party, for the president of the United States and for the country at large," said Sen. Bill Frist (R-Tenn.), the chairman of the National Republican Senatorial Committee.

In a fitting windup to an extraordinary two years, the election returns the Senate basically to where it was when Bush took office and before Vermont Sen. James M. Jeffords bolted the GOP in June 2001, became an independent and aligned himself with the Democrats to give them their one-vote margin of control.

It also returns Sen. Trent Lott (R-Miss.) to the post of majority leader, which he relinquished to Sen. Thomas A. Daschle (D-S.D.) when the Senate changed hands. Both have indicated they will run again for their party posts, probably without opposition.

The changeover of power is likely to occur -- or at least begin -- when the Senate convenes for a post-election session next Tuesday. Because Talent was chosen in a special election to fill out the remaining four years of the term, he will take office as soon as his election is certified.

For Bush, the transfer of power means he will have a formidable edge in dealing with an all-Republican Congress during the two years leading up to the 2004 election. Republicans will control both committees and the legislative flow on the Senate floor.

Bush will have a far easier time winning Senate confirmation for his conservative judicial nominees, many of whom were blocked or stalled by the Democrats. He also faces fewer obstacles in trying to make his 2001 tax cuts permanent and cutting other taxes, encouraging oil and gas drilling in Alaska and elsewhere, and helping "faith-based" charities. A Republican Senate is also likely to speed approval of his proposal for a new Department of Homeland Security.

But Bush will lose one advantage he had with the Democrats in control: He can no longer blame Daschle and his party for failures, as he did frequently on issues such as energy and the Homeland Security Department.

Democrats will be losing their only existing power base in Washington and much of the leverage they have had to block or reshape Bush initiatives. They could still use Senate rules to slow the administration down, but, without control of committees and the Senate agenda, their powers will be sharply curtailed.

The switch could also affect the future for Daschle, who has been mentioned as a possible presidential contender for 2004.

"We knew we had an uphill battle to begin with, and I think it played out tonight," said Sen. Patty Murray (D-Wash.), the chairwoman of the Democratic Senatorial Campaign Committee.

Republicans achieved their victory by holding onto GOP-held seats in all but one key battleground state and chipping away at vulnerable Democratic incumbents, many of whom were running in states carried by Bush two years ago.

Republican Elizabeth Hanford Dole triumphed over Democrat Erskine Bowles, President Bill Clinton's White House chief of staff, to claim the seat held by retiring Sen. Jesse Helms (R-N.C.). In New Hampshire, Rep. John E. Sununu (R) turned back retiring Gov. Jeanne Shaheen in a race that had prompted high hopes among Democrats for a gain. Sununu defeated Sen. Robert C. Smith (R) in the GOP's September primary.

In a significant upset, Rep. C. Saxby Chambliss (R) unseated Sen. Max Cleland (D) in Georgia. Until the race narrowed in the closing weeks of the campaign, Democrats thought Cleland would be a likely winner.

Also tight was the race in South Dakota, where incumbent Sen. Tim Johnson (D) was trailing Rep. John Thune (R) by about 3,000 votes with nearly 90 percent of the votes counted. And in one of the highest profile races, former Vice President Walter F. Mondale and Republican Norm Coleman were locked in a hotly contested faceoff in Minnesota to succeed the late Sen. Paul D. Wellstone (D), who died in a place crash Oct. 25.

Mondale trailed Coleman, 50 percent to 47 percent, early this morning. But with fewer than half the precincts reporting, the former vice president still had a chance of pulling it out. Election officials said the final results could be delayed because the supplemental Senate ballots printed at the last minute with Mondale's name had to be counted by hand instead of optical scanners.

Coleman appeared to be running strongly in the suburbs of the Twin Cities area, traditional GOP strongholds, while Mondale was performing well in urban and rural areas, including northern Minnesota heavily populated with Democrats and union members. Many of the uncounted precincts are in the Minneapolis and St. Paul areas and northern Minnesota's Iron Range, where Mondale is expected to draw substantial support.

"Some of the best-looking precincts you ever saw in your life have yet to report," Mondale told supporters in St. Paul.

Arkansas was the major bright spot for the Democrats. State Attorney General Mark Pryor (D) unseated Sen. Tim Hutchinson (R), who had been hampered in his reelection effort by controversy over his divorce and remarriage to a Senate staff member. Pryor is the son of former Sen. David Pryor (D), whom Hutchinson succeeded in the Senate.

Former senator Frank R. Lautenberg (D-N.J.), making a comeback at age 78, defeated Republican Douglas Forrester for the New Jersey seat held by Sen. Robert G. Torricelli (D). Lautenberg, who left the Senate six years ago, was drafted for the race after Torricelli abandoned his campaign for a second term in a backlash over ethics problems.

Democrats' early hopes of staging an upset in the race to succeed 99-year-old Sen. Strom Thurmond (R-S.C.), who is retiring after the longest service ever in Congress, were dashed when Rep. Lindsey Graham (R) easily defeated former college president Alex Sanders.

Democrats were also disappointed in Texas where state Attorney General John Cornyn defeated former Dallas mayor Ron Kirk, the only African American in a Senate race, for the seat held by retiring Sen. Phil Gramm (R). In Tennessee, former GOP presidential hopeful Lamar Alexander defeated Rep. Bob. Clement (D) for the seat of retiring Sen. Fred D. Thompson (R).

In Colorado, Sen. Wayne Allard (R) fended off a challenge from Democrat Tom Strickland, whom he narrowly beat in his first bid for the Senate six years ago.

In Louisiana, Sen. Mary Landrieu (D) failed in a race against three Republican challengers to win 50 percent in the state's one-of-a-kind all-party primary. She will face a runoff, apparently against Suzanne Haik Terrell, on Dec. 7.

Among incumbents, Sens. Tom Harkin (D-Iowa), Max Baucus (D-Mont.) and Susan M. Collins (R-Maine), all of whom had once been considered vulnerable, won reelection without great trouble

Other winners of new six-year terms included Sens. John W. Warner (R-Va.), John D. "Jay" Rockefeller IV (D-W.Va.), Mitch McConnell (R-Ky.), Jeff Sessions (R-Ala.), Richard J. Durbin (D-Ill.), Thad Cochran (R-Miss.), Joseph R. Biden Jr. (D-Del.), Pat Roberts (R-Kan.), John F. Kerry (D-Mass.), Ted Stevens (R-Alaska), Chuck Hagel (R-Neb.), James M. Inhofe (R-Okla.), Jack Reed (D-R.I.), Mike Enzi (R-Wyo.), Carl M. Levin (D-Mich.), Pete V. Domenici (R-N.M.), Gordon Smith (R-Ore.) and Larry E. Craig (R-Idaho).

Sen. Frank Murkowski (R) won his bid for the governorship of Alaska and will appoint his successor after he is sworn in in early December.

One-third of the Senate's 100 seats were at stake in yesterday's voting, which featured more than the usual number of tossup races for a Senate that was already as closely divided as it had been in a half-century.

A dozen of the seats were in various degrees of contention, nine of them appeared too close to call based on pre-election polls, and as many as a half-dozen were rated as true tossups -- reflecting the close division of the country in its choice between the two major political parties. While two-thirds of the senators up for reelection this year had little if any opposition, political observers said they could not remember when so many races were up in the air so late in a campaign.

As the voting began, the Senate was evenly divided between the two parties, with Vermont Sen. James M. Jeffords, an independent, tilting control of the chamber in favor of the Democrats. It was Jeffords who, in June 2001, left the GOP and switched control of the Senate to the Democrats. But the interim appointment by Gov. Jesse Ventura of independent Dean Barkley in Minnesota could change the balance for at least part of the post-election session, starting next Tuesday. Barkley has not said which party -- if any -- he will align himself with when he comes to the Senate.

For the first time in years, Republicans had far more seats to defend than the Democrats -- 20 as opposed to 14 -- as a result of gains they made in earlier elections. They were also facing tough historical odds because the president's party normally loses seats in the midterm election.

Democrats had problems of their own, including the fact that most of their closest races were being fought in states carried by Bush in 2000, such as South Dakota, Missouri, New Hampshire, Georgia and Colorado. Also, although many of their individual candidates were well-financed, Democrats raised less as a party than Republicans did to help their candidates in critical races.

Even so, the two parties raised and spent record amounts on Senate races this year. The Democratic Senatorial Campaign Committee raised $109.5 million during the first 21 months of the election cycle, compared with $115.7 million raised by the National Republican Senatorial Committee.

Republican Elizabeth Dole, right, gets a kiss from her husband, former senator Robert J. Dole, after she won the U.S. Senate race in North Carolina. U.S. Sen. John Kerry (D-Mass.) kisses his wife, Teresa Heinz, as he claims victory in his bid for reelection. Kerry defeated Libertarian Michael Cloud.Rep. John E. Sununu (R-N.H.), right, and Sen. Judd Gregg (R-N.H.) celebrate Sununu's victory over Gov. Jeanne Shaheen (D) for a U.S. Senate seat.