Boston , Massachusetts -LRB- CNN -RRB- -- Republican Scott Brown won a major upset victory in Tuesday 's special election for the U.S. Senate seat formerly held by liberal Democrat Ted Kennedy . Brown defeated Massachusetts Attorney General Martha Coakley , the Democratic candidate . Brown 's victory made real the once unthinkable prospect of a Republican filling the seat held by Kennedy , known as the liberal lion , for almost 47 years until his death from brain cancer in August . Voters across Massachusetts braved winter cold and snow for an election with high stakes -- the domestic agenda of President Obama , including his priority of health care reform . Brown 's victory strips Democrats of the 60-seat Senate supermajority needed to overcome GOP filibusters against future Senate action on a broad range of White House priorities . Senate Democrats needed all 60 votes in their caucus to pass the health care bill , and the loss of one seat imperils generating that support again for a compromise measure worked out with the House . In a subdued concession speech , Coakley said she expected a tough assessment of her loss and lots of `` Wednesday-morning quarterbacking '' after losing a seat held by Democrats for more than 50 years . `` I am heartbroken at the result , '' Coakley said , later adding : `` Although I am very disappointed , I always respect the voters ' choice . '' Massachusetts Secretary of State Bill Galvin said last week that certifying Tuesday 's election results could take more than two weeks -- potentially enough time to allow congressional Democrats to pass a final health care bill before Brown is seated . But multiple Democratic sources said this is unlikely . Even if House and Senate Democrats could reach a deal to meld their bills and pass them in the next couple of weeks , there would be a huge outcry from not only Republicans , but also an increasingly distrustful public if they appeared to be rushing it through . Galvin had predicted as many as 2.2 million of the state 's 4.5 million registered voters would vote -- at least double the turnout from December 's primary . In one sign of high interest , more than 100,000 absentee ballots were requested ahead of the election , according to Galvin 's spokesman , Brian McNiff . Coakley was initially expected to easily win the race to replace Kennedy , who made health care reform the centerpiece of his Senate career . Until recently , Brown was underfunded and unknown statewide . In addition , no Republican has won a U.S. Senate race in Massachusetts since 1972 , and Democrats control the governorship , both houses of the state legislature , and the state 's entire congressional delegation . However , Brown surged in the weeks preceding Tuesday 's vote and led in all the final polls . Democratic sources told CNN that Coakley called Brown on Tuesday night to concede . In a sign of the high stakes involved , the Coakley campaign held an afternoon news conference Tuesday to complain that voters in three places received ballots already marked for Brown . iReport : Send us your thoughts on the special election McNiff confirmed that the secretary of state 's offices received two reports of voters saying they got pre-marked ballots . The suspect ballots were invalidated and the voters received new ballots , McNiff said . Kevin Conroy , the Coakley campaign manager , said the `` disturbing incidents '' raised questions about the integrity of the election . In response , the Brown campaign issued a statement criticizing Coakley 's team . `` Reports that the Coakley campaign is making reckless accusations regarding the integrity of today 's election is a reminder that they are a desperate campaign , '' Daniel B. Winslow , the counsel for the Brown campaign , said in the statement . Obama has been both `` surprised and frustrated '' by the race , White House Press Secretary Robert Gibbs said Tuesday . Obama and former President Bill Clinton hit the campaign trail over the past three days in an attempt to save Coakley 's campaign , which observers say was hampered by complacency and missteps . Obama crushed Sen. John McCain in Massachusetts in 2008 , beating the GOP presidential nominee by 26 points . `` If you were fired up in the last election , I need you more fired up in this election , '' Obama urged a crowd at a Coakley campaign rally on Sunday . Vicki Kennedy , the late senator 's widow , called on state Democrats to turn out to save her husband 's legacy . `` We need your help . We need your support . We need you to get out there and vote on Tuesday , '' Kennedy said . `` We need you to bring your neighbors . We need you to bring your friends . '' Brown , who has trumpeted his 30 years of service in the National Guard , hewed to traditional GOP themes at the end of the campaign . He promised at a rally Sunday that , if elected , he would back tax cuts and be tougher on terrorists than Coakley . He also repeated a pledge to oppose Obama 's health care reform effort . `` Massachusetts wants real reform and not this trillion-dollar Obama health care that is being forced on the American people , '' he said . `` As the 41st -LSB- Republican -RSB- senator I will make sure that we do it better . '' Forty-four percent of Massachusetts voters cited the economy and jobs as their top concern in a recent 7 News/Suffolk University poll . Thirty-eight percent mentioned health care as their top concern . Voters more concerned with the economy were split almost evenly between the two candidates ; voters more worried about health care narrowly supported Coakley . Brown 's surprising strength came in part because some independents and conservatives who have supported Democrats in the past were having second thoughts . Democrats far outnumber Republicans in Massachusetts , but there are more independents than Democrats and Republicans combined . Several Democratic sources say multiple Obama advisers have told the party they believed Coakley was going to lose , despite Obama 's campaign appearance for Coakley on Sunday . Facing the possibility of Coakley 's defeat , Democrats were trying to figure out if they could pass health care reform without that crucial 60th Senate vote . The seat is currently held by former Kennedy aide and longtime friend Paul Kirk , who was appointed to the seat on an interim basis . Two Democratic sources in close contact with the White House told CNN on Monday they 've urged the administration , in the event of a Brown victory , to push House Democrats to pass the Senate 's health care bill as currently written . Doing so would prevent the plan from having to be taken up by the Senate again . `` I think the Senate bill clearly is better than nothing , '' House Majority Leader Steny Hoyer , D-Maryland , said Tuesday . A third option would be for Democrats to revisit the idea of trying to push health care through the Senate with only 51 votes -- a simple majority . But to do that Democrats would have to use a process known as reconciliation , which presents technical and procedural issues that would delay the process for a long time . A number of Democrats are eager to put the health care debate behind them and move on to economic issues such as job creation as soon as possible this election year . Senate Democrats could also try again to get moderate GOP Sen. Olympia Snowe of Maine to vote for a compromise health reform plan . Multiple Democratic sources , however , have said they believe that is unlikely now . CNN 's Jim Acosta , Dana Bash , Kevin Bohn , Ed Henry , Ed Hornick , John King , Suzanne Malveaux , Shawna Shepherd , Jessica Yellin , Alan Silverleib and Tom Cohen contributed to this report .