Shock poll victory leaves Obama reeling

In a stunning blow to President Barack Obama, Republican Scott Brown won a bitter US Senate race in Massachusetts last night and promised to be the deciding vote against his sweeping healthcare overhaul.

Brown's win robbed Democrats of the crucial 60th Senate vote they need to pass the healthcare bill and sent shudders of fear through Democrats facing tough races in November's congressional elections.

What once seemed an easy Democratic victory turned into a desperate scramble in the last few weeks as Brown surged ahead of Democratic state Attorney General Martha Coakley on voter fears over the economy, the healthcare bill and Obama's agenda.

Brown, a Massachusetts state senator, said he would be the pivotal 41st Republican vote against the healthcare overhaul in the 100-member Senate.

"People don't want this trillion-dollar healthcare plan that is being forced on the American people," Brown told cheering supporters at a Boston hotel who chanted "41" and "Seat him now."

He said voters rejected the closed-door deals that were driving the healthcare debate, and he took satisfaction in proving the experts - and Democrats - wrong.

"They thought that they owned this seat. They thought that they couldn't lose," Brown said. "You all set them straight."

Brown's upset with 52 per cent of the vote in heavily Democratic Massachusetts raised the specter of large losses for Democrats across the country in November and left the party scrambling to find answers.

"Anyone who has been out on the campaign trail has seen the anger," Coakley, who was criticized for running a weak campaign, told a room of dispirited supporters at a Boston hotel. "I am heartbroken at the result."

Obama, who won almost 62 per cent of the state's vote in the 2008 presidential election, made a last-minute appeal in Massachusetts on Sunday to try to ignite enthusiasm for Coakley's campaign to replace the late Senator Edward Kennedy, a Democratic icon and longtime champion of healthcare reform.

In Washington, Obama spokesman Robert Gibbs said the president called Brown after the result.

"The president told Senator Brown that he looks forward to working with him on the urgent economic challenges facing Massachusetts families and struggling families across our nation," Gibbs said in a statement.

Expectations the Brown victory could be the death knell for healthcare reform drove health insurance and drug company stocks higher on Tuesday, lifting the Dow and the S&P 500 to 15-month closing highs.

US Senate Democratic leader Harry Reid said he would welcome Brown to the Senate as soon as he received the paperwork from Massachusetts officials.

"I believe it would only be fair and prudent that we suspend further votes on healthcare legislation until Senator-elect Brown is seated," Democratic Senator Jim Webb said.

Massachusetts last elected a Republican to the Senate in 1972, but the shift could not have come at a worse time for Obama. Democrats control 60 votes in the Senate to 40 for the Republicans, and the loss of one Democrat could doom the healthcare bill.

Democratic leaders vowed to push healthcare reform through Congress despite the results, but several Democrats cautioned the party to reconsider its stance.

"It wouldn't be the worst thing in the world to take a step back and say we're going to pivot to do a jobs thing," Representative Anthony Weiner of New York told reporters.

Republicans said the results confirmed the public's distaste for Obama's healthcare overhaul and their anger at being ignored by Democratic lawmakers.

"The voters in Massachusetts, like Americans everywhere, have made it abundantly clear where they stand on healthcare. They don't want this bill and want Washington to listen to them," Republican Senate leader Mitch McConnell said.

Millions of dollars had flooded into the state to buy nonstop television advertising for both sides, transforming a relatively sleepy contest into a bitter brawl.