The Republican Party attempts to break the mould with different candidates for the upcoming mid-term elections
Spurred on by figures such as Sarah Palin, the former Alaska governor, and Glenn Beck, the Fox News commentator, the movement is set on moving the Republican party further to the right. The 18 per cent of Americans who identify themselves as tea party supporters tend to be Republican, white, male, married and older than 45, according to a New York Times and CBS News poll in April.
They hold more conservative views than Republicans generally and while most party members say they are "dissatisfied" with Washington, tea party supporters are more likely to classify themselves as "angry," the poll found. The movement has
come off the boil since last summer, when their anger at healthcare reform led to
raucous scenes at protests and town halls around the country. There, they compared Mr Obama to Adolf Hitler or told him to "go home to Kenya".
Even Ken Buck, who won the Republican Senate primary in Colorado on the back of tea party support, thinks some of the activists
are too fringe. He was caught on tape
exhorting "those dumb-asses at the tea party" to stop asking him whether Mr Obama was born in America.
This primary season is showing that the tea party, even if less energised than last year, remains
a political force to be reckoned with. But it also remains to be seen just how influential the movement will be on November 2, when all 435 House seats and 36 Senate seats will be up for grabs.
Good news for the Democrats
Democrats in many districts will be relieved to be competing against tea party candidates who are seen as novices or extremists. "What should have been pretty easy wins for the Republicans in places like Florida and Nevada are in danger because of the mobilisation of the tea party candidates," said Thomas Mann, a congressional expert at the Brookings Institution.
The Republican establishment insists that their candidates are "very electable". "Democrats want us to get upset but the fact is that tea party involvement is a very good thing because they are very active and very organised, and they will turn out in November," said Doug Heye of the Republican National Committee.
Norman Ornstein, of the American Enterprise Institute, said some of the unconventional picks will end up being better candidates than their histories might suggest. "And some of them will succeed because people are pissed [off]," Mr Ornstein said. "
Turnout is high when people are pissed [off] and voters are going to be less concerned about whether a candidate's views are outside the mainstream."
Mr Mann said it was unclear how successful they would be in the long term: "The party has clearly tilted to the right, driven in large part by the tea party movement. That may not hurt them in 2010 but it is likely to affect the way they comport themselves in office and it would boost Obama in 2012."