By Richard Lister
BBC News, Washington
Scott Brown's campaign was seen as superior to that run by Martha Coakley
In Boston last August, I watched thousands of people wait patiently to pay their respects to the late Senator Edward Kennedy as he lay in repose at the memorial library dedicated to his brother John.
He'd been Senator since 1962, and JFK won the seat before him, in 1952. That it would stay in Democratic hands was a foregone conclusion.
Except it wasn't. The scale of this revolution in Kennedy country is causing jaws to drop in Washington and sending a chill through those Democrats facing re-election battles in November.
It was, of course, an election in one state, not a nationwide one, which means there are local factors to take into account.
Martha Coakley's campaign was widely criticised for being lacklustre and gaffe-prone. She even ridiculed the idea of standing in the cold to shake hands with baseball fans.
Edward Kennedy's successor has the power - and it seems the will - to pull healthcare reform back from the brink of becoming a reality
Scott Brown was a telegenic and energetic campaigner with military experience and an army commendation for his work after the 9/11 attacks. He set the pace for the campaign.
Democratic Party officials at state and national level are already blaming each other for failing to respond quickly enough to evidence that the Republicans were pulling away.
But there is no doubt that the vote also reflects a growing backlash against Democrats nationally.
President Barack Obama's approval ratings have slumped to about 50%, and those for the Democratic-controlled Congress are, according the Gallup, about half that.
In tough economic times - and the US unemployment rate is about 10% - voters tend to blame the party in power, and Mr Brown also made much of his ability to be the one vote in the Senate that Republicans need to block Mr Obama's healthcare reform plans - which again, polls suggest, most people in America are highly dubious about.
So this election leaves the Republican Party rejuvenated and with that vital 41st vote, which means - in theory - they can stall much of the Democrats' legislative agenda indefinitely.
Senator Kennedy was the only one of four brothers to die a natural death
The House and Senate have passed different healthcare reform bills, and negotiations are under way to turn them into one bill which both chambers can support.
Republicans say the Democrats' plans are too expensive and are unanimously opposed to them. Democrats need 60 votes to ensure the bill can go to President Obama to sign. Now they have just 59.
The alternatives for the Democratic leadership are to have the House vote on the bill the Senate has already passed.
But House Speaker Nancy Pelosi has suggested there are too many differences between the two bills to make that feasible.
The other possibility would be to rush a compromise bill through before Mr Brown takes his seat.
But that could well cause a political backlash against the Democrats in November - even if the two chambers could resolve their differences that quickly.
The great irony in all this is that Ted Kennedy was the foremost champion of reforms that would ensure that all Americans could get health insurance.
His death deprived the campaign of a key advocate and much needed Congressional dealmaker.
Now his successor has the power - and it seems the will - to pull healthcare reform back from the brink of becoming a reality.