Republicans fell short Tuesday night of their goal of winning control of the Senate, after a campaign beset with weak candidate recruitment and self-inflicted gaffes in some of the GOP’s most promising races.
From Massachusetts to Montana, in 10 competitive Senate contests, Republicans in late returns were poised to pick up as many as three Senate seats from Democrats. But Democrats also picked up at least three seats from the GOP, allowing Senate Majority Leader Harry Reid of Nevada and his troops to maintain their control of the chamber.
Mr. Reid, accusing Republicans of obstructionism in President Obama’s first term, said of the results, “This is what happens when your No. 1 goal is to defeat the president and not work together to get legislation passed.”
Heading into the election, Democrats held a 53-47 majority. Republicans were seeking to regain control of the chamber for the first time since 2006.
Across the map, races that had once looked promising for the GOP turned instead to victories for the Democrats. One of the biggest victories for the Democrats came in Virginia, where former Gov. Tim Kaine was declared the winner over Republican George Allen shortly before 11 p.m.
The GOP viewed the race as a prime chance for a pickup of the seat left open by the retiring Democratic Sen. Jim Webb.
Polling had shown a tight contest in Virginia throughout the fall campaign. With the presidential race also focusing intently on Virginia’s 13 electoral votes, Mr. Kaine was hoping to benefit from President Obama’s coattails.
In Maine, Democrats likely picked up a seat when former Gov. Angus King, an independent, won the race to replace retiring Republican Sen. Olympia J. Snowe. Mr. King is expected to caucus with the Democrats.
In Florida, incumbent Democratic Sen. Bill Nelson easily defeated Republican challenger Rep. Connie Mack, a race the GOP once thought winnable.
Among the contests that were not in doubt, Democratic Sen. Benjamin L. Cardin of Maryland easily won a second term over Republican Daniel Bongino and independent Rob Sobhani.
In Ohio, Democratic incumbent Sen. Sherrod Brown easily fended off a challenge from Republican Josh Mandel, the state treasurer. In Connecticut, Democratic Rep. Christopher S. Murphy defeated GOP nominee Linda McMahon convincingly.
Last summer, Republicans had high hopes that Mrs. McMahon could take over the seat of retiring Sen. Joe Lieberman, an independent who caucuses with the Democrats.
In Massachusetts, Democrat and consumer advocate Elizabeth Warren defeated incumbent Republican Sen. Scott P. Brown.
At the start of the two-year election cycle, Republican leaders expressed confidence about their chances of winning back the Senate. Democrats were facing an uphill battle to protect their majority, forced to defend 23 seats to only 10 for the GOP. Democrats also had lost four seats in the 2010 midterm election.
Giving Republicans even more hope were the retirement of Democratic incumbents in Hawaii, Nebraska, New Mexico, North Dakota, Virginia and Wisconsin.
Republicans had to deal with retirements only in Arizona, Texas and Maine. But the GOP’s plans suffered huge setbacks when its candidates in Missouri, Rep. W. Todd Akin, and in Indiana, state Treasurer Richard Mourdock, made controversial remarks about rape and abortion.
Mr. Akin, seeking to oust Democratic incumbent Claire McCaskill, told an interviewer in August that women’s bodies have a way of rejecting pregnancy in cases of “legitimate rape.” Mrs. McCaskill retained her seat.
Mr. Mourdock, who defeated six-term Sen. Richard G. Lugar in the GOP primary, said during a televised debate last month that a pregnancy resulting from rape was something “God intended.” He lost to Democratic Rep. Joe Donnelly.
Other Senate races included the contest in Nebraska to replace retiring Democrat Ben Nelson, who opted not to run after casting the deciding vote for President Obama’s health-care bill in 2010. Republican state Sen. Deb Fischer defeated Democrat Bob Kerrey, a former senator and governor. For much of the campaign, the Republican had led in the polls.
In North Dakota, Democrats nominated former state attorney general Heidi Heitkamp to replace retiring Sen. Kent Conrad, a Democrat first elected in 1986. Republicans nominated Rep. Rick Berg, who had led in most polls.
In Wisconsin, Democratic Rep. Tammy Baldwin, an openly gay member of Congress, won the race to replace retiring Democrat Herb Kohl, defeating former Republican Gov. Tommy G. Thompson, who acknowledged not having much energy for a vigorous campaign.
In Montana, Democratic Sen. Jon Tester appeared headed to victory over Republican Rep. Denny Rehberg, the state’s lone congressman. Mr. Rehberg, a former lieutenant governor, lost a bid for the Senate in 1996 to incumbent Democrat Max Baucus.
Republicans were fighting to hold onto the Senate seat in Nevada, where incumbent Sen. Dean Heller was running against Democratic Rep. Shelley Berkley.
In Pennsylvania, a late charge by Republican nominee Tom Smith, who made a personal fortune in the coal industry, fizzled against Democratic Sen. Bob Casey, son of the late governor.