Nancy Pelosi has represented the liberal enclave of San Francisco in the US House of Representatives for nearly 20 years, and she does not shy away from her left-of-centre beliefs. She is also known to invoke the skills she learnt as a mother of five when she needs to get the attention of a noisy crowd.

Mrs Pelosi is set to become the first female speaker of the House ? third in line to the presidency ? if, as polls suggest, Democrats take control in Tuesday’s mid-term elections. If she does, her tenure would also be shaped by something else: the “machine politics” she learnt as a child in Baltimore, where her father and, later, a brother, was mayor.

“She knows the iron law of reciprocity: I’ll help you if you help me,” said James Thurber, director of the Center for Congressional and Presidential Studies at American University in Washington. “She knows how things work.”

Mrs Pelosi, 66, appears ready to put those skills to the test. “Are you ready for a great Democratic victory?” she asked a cheering crowd near Philadelphia on Saturday at a get-out-to-vote rally.

She has been a leading critic both of President George W.?Bush, whom she called “incompetent” for his handling of the war in Iraq, and her Republican colleagues. But, in spite of the pleadings of some in her party, she insists that a Democratic- controlled Congress would not move to impeach Mr Bush.

“Democrats are proposing a new direction for all Americans, not just the privileged few,” she told the crowd, ticking off an ambitious six-part plan she said a new House would adopt in its first 100 hours of work. Her “Six in ’06” platform includes increasing the federal minimum wage, rolling back subsidies to oil companies, expanding stem cell research and cutting interest on student loans.

In recent weeks, Republicans have stepped up their attacks, holding out the spectre of a “San Francisco majority” as they struggle to keep control of Congress. “Nancy Pelosi and her Capitol Hill Democrats are way out of the mainstream on the issues people care strongly about,” John Boehner, Republican majority leader, said Saturday.

The strategy is a difficult one, with voters equally split between those who do and do not know who she is.

In the House, where her father also served, Mrs Pelosi is well known as an effective politician and aggressive fund-raiser ? and a liberal. She is a strong defender of abortion rights and a sharp critic of China’s human rights record.

She flexed her independence in 2002, when Dick Gephardt, then-Democratic leader in the House, went to the White House to show his support for the resolution authorising the use of military force in Iraq.

Mrs Pelosi insisted that supporters of the war had not shown clear evidence that Iraq posed an imminent threat to the US. She rounded up 126 Democratic votes against the resolution, while only 81 backed Mr Gephardt. The vote signalled a shift to a more aggressive stance in the Democratic caucus and set the stage for her election to minority leader in 2003, after Mr Gephardt resigned.

She has won high marks for keeping Democrats united and focused, imposing a surprising degree of discipline on a sometimes fractious group, as she acknowledged this year to The American Prospect.

“If I said: ‘A microphone is on the table is the message,’ 10 Republicans around the table would say a microphone is on the table, a microphone is on the table, a microphone is on the table. Ten Democrats around the table would say a microphone is on the table, it’s next to a glass, there’s all these people sitting around, it’s in a room with a chandelier, there are windows in the room...?Now why are you doing that? Just say what we’re going to say!”

If Democrats fail to capture the House, there will be pressure to find a new leader. But if Mrs Pelosi takes the Speaker’s gavel, the tensions within her party are likely to increase. Several long-serving liberals set to become committee chairmen are eager to pursue their agendas, while new members, including many moderates from the Midwest who would be part of a powerful bloc within the new majority, will urge a more cautious approach.

That dynamic will test Mrs Pelosi’s ability to combine the liberal, the mother and the machine politician. Professor Thurber expects her to follow the tradition of Democrats of the past.

“You change when you become Speaker,” Prof Thurber said. “You can’t push through a narrow liberal agenda on this House of Representatives, and she won’t.”

Copyright The Financial Times Limited 2006

"FT" and "Financial Times" are trademarks of the Financial Times.
c Copyright The Financial Times Ltd 2006.