The Democrats have suffered a defeat in the US midterm elections, but as Richard Wolffe writes for Channel 4 News there is not much to celebrate for the Republican Tea Party either.

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Normally elections are all about the winners. Tuesday's congressional elections in the United States have indeed left us with plenty of winners, most of them Republican. But the real story lies among the losers.

That's because the biggest loser, after the Democratic Party, was the Tea Party. Despite the enthusiasm of its supporters and its effective rebranding of Republicans, the Tea Party failed badly.

No less than four Tea Party candidates lost their Senate races. In the marquee race in Nevada, Sharron Angle was supposed to edge out the Democratic leader Harry Reid. Instead she lost by a surprisingly big five-point margin. In Delaware, the media darling Christine O'Donnell blew a double-digit lead to go down to heavy double-digit defeat. In Colorado, the Democrat Michael Bennet - who was appointed to his seat and never ran for elected office until this year - was in deep trouble all along but seems to have squeaked victory over Ken Buck.

And in the home state of the Tea Party's guru - in Sarah Palin's Alaska - Joe Miller appears to have squandered a huge lead to lose to a write-in candidate: the sitting Republican senator whom he beat in the primary, Lisa Murkowski. And her name is not exactly easy to write into a ballot paper.

If the Tea Party can't win in Alaska, where can it win? In Kentucky, Rand Paul turned a 30-point advantage into an 11-point win. And in Florida, Marco Rubio won in a three-way race that split the Democratic vote.

US midterms: not much to celebrate for the Tea Party (Reuters)

That's not exactly a resounding set of results for this new political force. Indeed, were it not for the Tea Party candidates, the Republican party would have surely won control of the Senate as well as the House.

There lies the escape tunnel for the White House, which otherwise lost heavily on Tuesday - not just in the House of Representatives, but also key governorships in battleground states. The Tea Party has reinvented the Republican brand but its candidates are deeply flawed and its instincts are anathema to the very independent voters who switched from backing Obama in 2008 to backing Republicans in 2010.

The extreme positions of the Tea Party - such as abolishing the Department of Education - as well as its hard line against any kind of compromise with Democrats, is precisely the kind of politics that unaffiliated independents abhor.

To be sure, if the economy remains stagnant and unemployment remains high, President Obama will be in trouble no matter what the political landscape looks like.

But if Sarah Palin and the Tea Party continue to dominate the Republican debate for the next two years, there are solid grounds for some very cautious optimism inside the White House, no matter how bleak this week's results.

Richard Wolffe

One more point worth keeping in mind: this looks like the third change election in a row in the United States. First Congress changed hands in 2006, then the White House in 2008, and now Congress again in 2010. That's six years of volatility. There's nothing in the polls, or the behaviour of politicians, to suggest that trend is going to end in 2012.

Richard Wolffe is a political analyst and contributor to NBC, and author of "Revival: The Struggle for Survival Inside the Obama White House". He was formerly Newsweek's Senior White House Correspondent.