The Republicans' shock victory in the election for the US Senate seat in Massachusetts meant the Democrats lost their supermajority in the Senate. This makes it even harder for the Obama administration to get healthcare reform passed in the US.
Political scientist Dr David Runciman looks at why is there often such deep opposition to reforms that appear to be of obvious benefit to voters.
Last year, in a series of "town-hall meetings" across the country, Americans got the chance to debate President Obama's proposed healthcare reforms.
What happened was an explosion of rage and barely suppressed violence.
Polling evidence suggests that the numbers who think the reforms go too far are nearly matched by those who think they do not go far enough.
But it is striking that the people who most dislike the whole idea of healthcare reform - the ones who think it is socialist, godless, a step on the road to a police state - are often the ones it seems designed to help.
In Texas, where barely two-thirds of the population have full health insurance and over a fifth of all children have no cover at all, opposition to the legislation is currently running at 87%.
Instead, to many of those who lose out under the existing system, reform still seems like the ultimate betrayal.
Why are so many American voters enraged by attempts to change a horribly inefficient system that leaves them with premiums they often cannot afford?
Why are they manning the barricades to defend insurance companies that routinely deny claims and cancel policies?
It might be tempting to put the whole thing down to what the historian Richard Hofstadter back in the 1960s called "the paranoid style" of American politics, in which God, guns and race get mixed into a toxic stew of resentment at anything coming out of Washington.
But that would be a mistake.
If people vote against their own interests, it is not because they do not understand what is in their interest or have not yet had it properly explained to them.
They do it because they resent having their interests decided for them by politicians who think they know best.
There is nothing voters hate more than having things explained to them as though they were idiots.
As the saying goes, in politics, when you are explaining, you are losing. And that makes anything as complex or as messy as healthcare reform a very hard sell.
Stories not facts
In his book The Political Brain, psychologist Drew Westen, an exasperated Democrat, tried to show why the Right often wins the argument even when the Left is confident that it has the facts on its side.
He uses the following exchange from the first presidential debate between Al Gore and George Bush in 2000 to illustrate the perils of trying to explain to voters what will make them better off:
Gore: "Under the governor's plan, if you kept the same fee for service that you have now under Medicare, your premiums would go up by between 18% and 47%, and that is the study of the Congressional plan that he's modelled his proposal on by the Medicare actuaries."
Bush: "Look, this is a man who has great numbers. He talks about numbers.
"I'm beginning to think not only did he invent the internet, but he invented the calculator. It's fuzzy math. It's trying to scare people in the voting booth."
Mr Gore was talking sense and Mr Bush nonsense - but Mr Bush won the debate. With statistics, the voters just hear a patronising policy wonk, and switch off.
For Mr Westen, stories always trump statistics, which means the politician with the best stories is going to win: "One of the fallacies that politicians often have on the Left is that things are obvious, when they are not obvious.
"Obama's administration made a tremendous mistake by not immediately branding the economic collapse that we had just had as the Republicans' Depression, caused by the Bush administration's ideology of unregulated greed. The result is that now people blame him."
Thomas Frank, the author of the best-selling book What's The Matter with Kansas, is an even more exasperated Democrat and he goes further than Mr Westen.
He believes that the voters' preference for emotional engagement over reasonable argument has allowed the Republican Party to blind them to their own real interests.
The Republicans have learnt how to stoke up resentment against the patronising liberal elite, all those do-gooders who assume they know what poor people ought to be thinking.
Right-wing politics has become a vehicle for channelling this popular anger against intellectual snobs. The result is that many of America's poorest citizens have a deep emotional attachment to a party that serves the interests of its richest.
Thomas Frank says that whatever disadvantaged Americans think they are voting for, they get something quite different:
"You vote to strike a blow against elitism and you receive a social order in which wealth is more concentrated than ever before in our life times, workers have been stripped of power, and CEOs are rewarded in a manner that is beyond imagining.
"It's like a French Revolution in reverse in which the workers come pouring down the street screaming more power to the aristocracy."
As Mr Frank sees it, authenticity has replaced economics as the driving force of modern politics. The authentic politicians are the ones who sound like they are speaking from the gut, not the cerebral cortex. Of course, they might be faking it, but it is no joke to say that in contemporary politics, if you can fake sincerity, you have got it made.
And the ultimate sin in modern politics is appearing to take the voters for granted.
This is a culture war but it is not simply being driven by differences over abortion, or religion, or patriotism. And it is not simply Red states vs. Blue states any more. It is a war on the entire political culture, on the arrogance of politicians, on their slipperiness and lack of principle, on their endless deal making and compromises.
And when the politicians say to the people protesting: 'But we're doing this for you', that just makes it worse. In fact, that seems to be what makes them angriest of all.