The Tea Party insurgency sweeping through the US Republican Party has claimed its first sitting senator, dramatically raising the stakes for the mid-term elections in November.
Bob Bennett, a three-term senator from Utah, blamed a "toxic" political environment for his defeat at the hands of the anti-establishment, anti-government movement in the party's pre-election convention.
Two Tea Party-supported candidates will now fight for the nomination in Utah, in a result that alarmed sitting Congressmen not just from the Republican Party but Democrats, too.
Disapproval of Washington is at levels not seen since 1994, when Republicans swept into power in the House of Representatives and hobbled the Clinton presidency. Senator Bennett, 77, had come under fire from the right for supporting the bailout of the financial system in 2008 and proposing a bipartisan healthcare bill.
In an emotional speech after he came third in Saturday's vote, he said: "The political atmosphere obviously has been toxic, and it's very clear that some of the votes I have cast have added to the toxic environment.
"Looking back on them, with one or two very minor exceptions, I wouldn't have cast any of them any differently, even if I had known at the time they were going to cost me my career."
The Tea Party movement, whose spiritual guide is the former Alaskan governor and vice-presidential candidate Sarah Palin, has been flushing away moderate Republican candidates across the US.
It is organised loosely around policies of low taxes, minimal government and cuts to public spending. Senior figures have abandoned the Republican Party as a result of its growth.
In Florida, Governor Charlie Crist is running for senate as an independent after former state House speaker Marco Rubio overtook him in the polls with the support of Tea Party activists. Arlen Specter, senator for Pennsylvania, switched to the Democrats after facing a challenge to his re-election.
Some of the party's most famous names are fighting stiff challenges, including Senator John McCain in Arizona and Mitch McConnell, Senate Republican leader, in Kentucky.
The civil war in the party is forcing its major figures to tack to the prevailing mood. Rudy Giuliani, former Republican presidential candidate, said yesterday: "Obama has pushed the envelope so far, we need candidates effective in standing up to the inexorable march of European social democracy."
The Utah Senate seat is one of the safest for Republicans and Mr Bennett had been popular. The endorsement of Mitt Romney, feted for saving the 2002 Winter Olympics, failed to aid him.
The Tea Party's favourite candidate, Mike Lee, who came second, called for a new generation of leaders "committed to constitutionally limited government". Tim Bridgewater, a local businessman also promising to fight against huge budget deficits, topped the poll.