The arch-conservative US Tea Party movement, fueled by anger at President Barack Obama and the sour economy, now faces a defining test of its strength and future in Tuesday's elections.
The outcome may decide whether the loosely knit network, which has shaken up US politics despite lacking central headquarters, formal leaders, or a slate of official candidates, has staying power beyond the bitter 2010 campaign.
The group draws much of its strength from a wing of the Republican party that views government with deep suspicion and preaches cuts in taxes and government spending as the solution to sluggish growth.
Tea Party standard-bearers made headlines by shocking establishment Republicans in Alaska, Delaware, Kentucky, Nevada and Utah primaries -- and by taking controversial stances party insiders fear may scare off independents.
Republican insiders predict the group's energy will help power big gains in the congress next week. They hope that anger at the economy will lead voters to overlook comments that in another election year might doom a candidacy.
"Voters today seem to respond a lot less critically to 'gotcha' moments than they have in the past," according to a Republican party strategist in Washington, who requested anonymity to speak candidly about the movement.
Democrats, who fear losing the House of Representatives and seeing their Senate majority sharply reduced, have gleefully highlighted gaffes and eyebrow-raising moments from Tea Party candidates.
Some have raised the prospect of armed uprisings if they lose, branded the global scientific consensus on climate change a "hoax," and condemned landmark civil rights legislation -- then quickly backtracked in the face of an outcry.
A key test of the dueling approaches will come in Nevada, where Democratic Senate Majority Leader Harry Reid is fighting for his political life against Tea Party candidate Sharron Angle, whom he narrowly trails in some polls.
Reid has branded Angle as too extreme to be given the reins of government, and she has tarred him as an career politician in lockstep with the Obama White House.
Another open question relates to how Tea Party Republicans will govern, and how their often tense relationship with establishment and moderate Republicans will affect the party after November 2.
"It will be a relationship best described as 'trust but verify,' according to Todd Harris, a top strategist for Republican Senate hopeful Marco Rubio of Florida, a Tea Party darling who is favored to win.
Harris, whose words echoed Republican icon Ronald Reagan's comment about US arms control treaties with the Soviet Union, said the Tea Party expected the new congress "to take action on big parts of its agenda."
Republican House Minority Leader John Boehner, who has courted the group, recently ruled out any "compromise" in plans to attack Obama's signature health care overhaul -- a top Tea Party target.
"We're going to do everything -- and I mean everything we can do -- to kill it, stop it, slow it down, whatever we can," said Boehner, who is all but sure to become House Speaker if his party retakes the chamber.
In the Senate, Republican Minority Leader Mitch McConnell has made defeating Obama in the 2012 White House race the party's top goal, while warning against the kind of ideology-driven overreach that helped president Bill Clinton coast to reelection in 1996 after losing congress in 1994.
"But the level of enthusiasm surrounding the Tea Party and the anger that exists with the electorate this cycle aren't going away after next Tuesday," said Harris. "This is something that's going to carry on well into the next presidential election and potentially largely shape it."
The movement's critics aren't going away, either: Democrats and some commentators have underlined that longtime Republican insiders have raised vast sums to fund the self-described outsiders.
Others have noted that, while the Tea Party may get its name from a storied anti-tax demonstration ahead of the US revolution to cast off British rule, it burst onto the US political scene after a television journalist ranted against helping Americans facing foreclosures, dubbing them "losers."