As a result, four of the five lost their reelection contests, including Rep. Martin Frost, a former party leader and the longest-serving member of the Texas congressional delegation, and Rep. Charles W. Stenholm, a conservative Democrat who had held his seat since 1979 and was the ranking member on the House Agriculture Committee.
The only survivor among the five was Rep. Chet Edwards, who held off his Republican challenger by 51 percent to 47 percent in a central Texas district that includes President Bush's Crawford ranch.
Perhaps the biggest loser in Tuesday's legislative races was Daschle, 56, who had been targeted by the Republican leadership as an obstacle to the Bush administration's agenda. He lost to Thune, 43, by 4,535 votes out of more than 391,000 cast. A former House member, Daschle first won election to the Senate in 1986 and became minority leader in 1994.
In Alaska, Democrat Knowles charged that Murkowski got her Senate seat through nepotism rather than merit. Her father, Frank Murkowski, appointed her to the seat he had occupied after he was elected governor two years ago.
But Murkowski campaigned hard and argued that Alaska would benefit from keeping intact the state's GOP team consisting of her father, herself and Sen. Ted Stevens, chairman of the Appropriations Committee.
The overall results were a resounding disappointment to Democrats, who were hoping to exploit the closeness of as many as 10 of the 34 Senate races this year to retake control of the Senate.
Although the expanded GOP margin in the Senate would still be well short of the 60 needed to push through legislation without risk of Democratic filibusters, the strengthened position could ease the passage of major legislation and the approval of judicial appointments. Senate Majority Leader Bill Frist (R-Tenn.) would be far less dependent on the votes of a group of moderate Republicans from the Northeast to pass legislation.
There were two bright spots for the Democrats: the overwhelming victory of Obama in his bid to succeed retiring U.S. Sen. Peter Fitzgerald (R) and Democrat Ken Salazar's victory over Republican Pete Coors for the Colorado Senate seat held by retiring GOP Sen. Ben Nighthorse Campbell.
Obama easily won in Illinois, defeating Republican Alan Keyes in the first Senate race between two African Americans.
Although Coors's role as chairman of Coors Brewing Co. gave him instant name recognition throughout Colorado, Salazar was able to offset that advantage by capitalizing on his ties to the Hispanic community and his experience as state attorney general.
For a while yesterday, it appeared that Democrats might pick up another Republican-held seat, that of veteran Sen. Arlen Specter (R-Pa.). However, Specter, a GOP moderate who earlier this year survived a tough primary challenge from a more conservative opponent, defeated Rep. Joseph M. Hoeffel III (D-Pa.).
A surprisingly strong Democratic challenge also fell short in Kentucky, where Republican Jim Bunning defeated Democrat Daniel Mongiardo, a little known Democratic state senator.
In Oklahoma, former representative Tom Coburn (R) defeated Rep. Brad Carson (D) for the seat of retiring Sen. Don Nickles (R), spoiling Democratic hopes for a takeover there.
In the Georgia Senate race, three-term Rep. Johnny Isakson (R) defeated Rep. Denise L. Majette (D) to claim the seat of retiring Democratic Sen. Zell Miller. The maverick Miller has long been estranged from the Democrats, and he delivered the keynote address at the Republican National Convention this summer.
