Conservative activists calling themselves the Tea Party arrived on the political scene in 2009. Candidates backed by the anti-establishment movement won several victories over mainstream Republicans in primary contests ahead of November's mid-term elections.
Here four voters from across the US explain why they support the Tea Party movement and what they expect from the forthcoming vote.
Judah Sekscinski, 26, banking, Newark, Delaware
I've been an active member of the Tea Party movement since it started.
The main reason I joined is because public spending has got out of control. We have a vast debt that we have to deal with or we'll just end up passing it on to our children and grandchildren.
I don't think it makes sense to spend our way out of recession. And the trillions we have spent haven't helped - unemployment is still high and small businesses are not thriving.
It's also time we changed some of the faces in Washington.
I attend rallies and I also try to spread the Tea Party message via social media. I've met a lot of people in the movement. Some are conservatives, some libertarians and a few fiscally conservative Democrats. So the thing that unites us is our concern for financial responsibility.
We're the realistic face of 21st Century conservatism. Under the Bush regime, and now under Obama, too many politicians are simply ignoring the major problems we have to fix - particularly the deficit.
I was so happy when Tea Party candidate Christine O'Donnell won the primary here in Delaware. This is quite a Democratic state but I think she is starting to turn the tide and could go on to win.
There are a lot of independents and Blue Dog [conservative] Democrats who supported Obama but are now disillusioned with the state of things and will support Tea Party people like Ms O'Donnell.
There will be a lot of change in November, but not the kind that was promised in 2008 by Obama. The Tea Party is here to stay, whether it becomes a faction of the Republican Party or whether it goes on to become a third party.
Jan Allen, 60, executive assistant, Milwaukee, Wisconsin
The Tea Party is not just Republicans. I am an independent and I support the movement.
I've seen a lot of presidential elections in my time, and I think we need something different.
We need a strong multi-party system with different groups in Congress.
The Tea Party could help us get there. They could become a third group of independent-minded politicians who align with other parties on an issue-by-issue basis.
Tea Party candidates are right to emphasise a return to the values of our Constitution.
We must return more power to the states and reduce federal oversight. Federal government passes far too many laws that are not properly funded, which leads to the states having to raise taxes to pay for them.
We also need to kick the incumbents out! There are too many people who have been elected year after year and see their job as an entitlement. It's time for some fresh faces.
I think the silent majority have found their voice, and they're speaking through the Tea Party. They have made progress in local, regional and state elections.
You'll see in November - the Tea Party will turn up. The movement just needs to get rid of some those on its radical fringe, and stick to the basics and they could make great strides.
David Kimber Howard, 60, stock trader, Orangevale, California
I am a member of South Placer County Tea Party Patriots, a local organisation. My wife is also an active member and I take my two kids to Tea Party rallies.
I got involved with the Tea Party a little over a year ago because I felt the country was simply heading in the wrong direction.
The federal debt is at such a level now that we simply won't be able to pay it off. I'm worried the government will tackle this by printing money and destroying our currency. This will lead to spiralling living costs.
I'm also worried about unconstitutional government. I'm fed up with judges repeatedly over-ruling voters' initiatives in California - from issues of illegal immigration, to gay marriage to firearm ownership.
The Tea party has grown rapidly and is tapping into a vast reservoir of disapproval with the current state of politics. I recently stuck a party sign in my lawn and three or four neighbours came to my house wanting to know how to get involved.
I laugh when people say the Tea Party are a bunch of extremists. All the people I've met in the movement are friendly, outgoing and very polite. Recently I attended a rally of around 12,000 people. There was no trouble at all, and there was no litter left at the end of the rally.
This November we can succeed in throwing out a lot of incumbents - from the local school board all the way up to the Senate.
Kevin Brent, 40, defence contractor, Fredericksburg, Virginia
Both main parties are elitist. Washington is full of the same type of arrogant people who look down on those outside the system. These elites don't listen to people like me - we're just part of the country they fly over.
The Tea Party gives us a chance to change the Republican Party from the inside so that it responds to people like me.
For too long the ruling class has infested the Republicans like a disease. They have not supported people of conservative values, but instead have collaborated with the Democratic Party.
The Tea Party is right to attack big government. The government tries to interfere with every aspect of people's lives. There are far too many laws, and far too much burden on business.
I'm worried about the deficit. If we don't do something about our national debt, I fear that by time I'm 55 I'll be taxed half my income to pay for it. If we don't do something young people will be on the streets - there will be civil disobedience, or worse.
We also need to repeal healthcare reform. The new system limits people's choices, forcing them to take up insurance. I'm worried that the reforms will mean healthcare rationing.
The reason that the Republicans lost big in 2006 and 2008 was because there were too few real conservatives running. Now we have different people running the show. I think the Tea Party surge will mean conservatives win many seats in November.
If we do win many seats I think people will be surprised by the changes - from repeal of healthcare reform to cuts in social security.