She says Obama is making the US 'a nation of slaves' – and her campaign is raking in millions. So just how far can Michele Bachmann go?

As stereotypes go, "Minnesota nice" is not a bad one. It holds that the mid-western residents of Minnesota, with its vast rural landscape and mostly Scandinavian-descended population, are unusually pleasant.

But Minnesotans might soon have to give up some of their hard-won reputation for quiet reasonableness thanks to one of their own, Congresswoman Michele Bachmann, a fiercely rightwing darling of the Tea Party, who is rapidly becoming one of the most famous politicians in America and may yet outshine Sarah Palin as a potential Republican presidential pick for 2012.

Bachmann, whose district is a sprawling stretch of farms and small cities, has used her theoretically modest political platform to catapult herself to the forefront of conservatism in America. She does not shy away from extreme opinions, lambasting President Barack Obama as a socialist threat to the American way of life. She is stridently anti-government, pro-business and socially conservative. She has even called for her fellow congressional politicians to be investigated to see if they are "pro-America" enough.

To many on the left of US politics, her outlandish statements seem a poor joke. She is regularly lampooned on liberal blogs in a similar manner to Palin, whose family life dominated the gossip magazines last week after the unexpected engagement of her daughter. But as Palin becomes more of a media force than a political one, Bachmann is rising to replace her. Her verve and anger have entranced a significant section of the population, one expected to vote in huge numbers in this November's mid-term elections. "Bachmann is media-savvy, energising and charismatic, just like Palin. But unlike Palin, she is a seasoned politician. She is not a political lightweight; she is serious," said Professor Shaun Bowler, a political scientist at the University of California at Riverside.

The populist Tea Party movement has shown a deep willingness to follow female leadership. Palin paved the way for Bachmann, but also other leading lights such as Sharron Angle in Nevada and Debra Medina in Texas. Some think women politicians suit its outsider mentality better than the usual Republican men. "These woman candidates provide the leadership that traditional male leaders cannot," said Steve Mitchell, chairman of the political consultancy Mitchell Research. Among the leading ladies of the US right, it is arguably Bachmann, not Palin, who is the biggest star. Confirmation of her rise came last week in the most definite form: cash.

Bachmann, who is campaigning for re-election in November, revealed that she had managed to raise $1.7m in the past three months. For a Minnesota congressional bid, that is a huge amount of money –far more than the $865,000 Palin raised in the same period and more, too, than was raised by the probable frontrunner for the Republican presidential nomination in 2012, the former Massachusetts governor Mitt Romney. Palin and Romney, of course, do not face the costs of an election this year; but many are now wondering if Bachmann might consider a White House run.

The force that has driven Bachmann to prominence is the Tea Party and the surge of rightwing anger in the country since Obama came into office. The movement is represented by numerous often squabbling organisations, but it has sent a jolt of energy through the Republican base and pushed the party to the right. Bachmann has been at the head of that move. She is probably the most popular elected politician with Tea Partiers. She has even sought to bring the Tea Party into Congress by setting up a Tea Party Caucus, which will be similar to congressional caucuses for black or Hispanic politicians. "The American people are doing their part and making their voices heard and this caucus will prove there are some here in Washington willing to listen," she said in a statement launching the group.

Bachmann is not unusual in touting the Tea Party's ideals of small government and spending cuts, but she does it in virulent language and also embraces many of the movement's fringe beliefs or extremist figures. She is due to star in a coming rightwing documentary called Socialism: A Clear and Present Danger, in which she says American citizens have become "indentured servants" of their government. The film uses clips of Obama alongside Stalin and Fidel Castro. "We need to reverse course so we can get back to freedom," she says.

She is a very savvy user of the conservative media – a familiar voice on the radio shows popular with Tea Party members and a darling of Fox News. That allows her to tap efficiently into the emotions and support of a resurgent conservative movement that is looking at the November polls with delight and expecting to wrest control of Congress back from the Democrats. "The Tea Party represents the wave of anger that we are seeing in America. These people can't wait to go to the polls. There might easily be a landslide," said Mitchell.

Indeed Bachmann's biography reads like that of a Tea Party member, blending politics, outrage and suburban life. She was born in Iowa and went to law school before moving to Minnesota to work for the US treasury, then left to become a full-time mother. It was a busy job. She and her husband, Marcus, have five children but have fostered 23 more.

Bachmann entered politics in 2000, after attending a political meeting for a state senate seat where she was dismayed at the liberalness of the Republican candidate. She decided to run, won the race, and then made it into Congress in 2006.

All along she has stressed her religious faith, saying that she and her husband fasted and prayed for three days before she decided to run for Congress. It is a potent mix: conservatism, Christianity and a gift for riding the biggest populist wave in American politics, all presented by a suburban mother of five.

But the wave Bachmann is riding may yet fail to reach the shore. Just as her rise exemplifies much of the strength and energy of the Tea Party movement, so too does she illustrate its weaknesses.

The Tea Party's organisation is untidy and dysfunctional and prone to squabbling. So too is Bachmann's. Last week, despite the amazing fundraising news, Bachmann's finance director, Zandra Wolcott, quit. Her chief of staff, Ron Carey – her fifth chief of staff in four years – also left.

Such a turnover might hurt any politician. But working for Bachmann does seem to be as wild as some of her opinions. She recently told a conservative conference that America was becoming a "nation of slaves" and that the Democrats had imposed "tyranny" on the country. "We are determined to live free or not at all," she said, using the language of the American Revolution. She wants to repeal Obama's healthcare reform and has said that it will literally kill sick patients rather than cure them. She has said that she does not want America to be a part of the international global economy. In the coming anti-socialist documentary, she talks of an appropriate tax rate of 10% because that is what the Bible suggests in the form of tithing. "We render to God that which is God's and the Bible calls for …maybe 10%," she says.

But that sort of comment – basing economic policy on scripture rather than actual economics – has a limited appeal to many mainstream voters. It causes the sort of damaging headlines that might make it impossible for Bachmann to extend her appeal beyond her base and into the vital middle ground. Bachmann may also be limited by her apparent links to extremist groups. The anti-socialist documentary was filmed by a church group that recently caused outrage by claiming that Hitler tried to kill Jews because he believed in evolution. At a conference this September, she is scheduled to speak alongside so-called "birthers" – those who believe Obama was born outside America and is therefore constitutionally barred from the role of president.

Bachmann, like the Tea Party movement as a whole, is a double-edged sword for the Republicans. While she has raised huge amounts of cash, so too has Tarryl Clark, the otherwise unknown Democrat running against her. Clark has raised $910,000 in the past three months – also more than Palin and all because she is facing Bachmann. The energy that the Tea Party generates brings strong support, but also guarantees fierce opposition. It could be enough to win the midterm elections, but not enough to prevent Obama winning a second term as president. It is enough to put Bachmann in the national spotlight, but not enough to put her in the White House.