Who is Christine O'Donnell?

After setting out to destroy him, Christine O'Donnell is one of a handful of Republicans who probably saved Barack Obama from complete humiliation in the 2010 mid-term elections.

Miss O'Donnell, 41, rode last year's Tea Party wave to win the Republican nomination for the US Senate seat in Delaware vacated by Joe Biden when he became Vice-President.

She inflicted a shock defeat on Mike Castle, the mainstream Republican candidate, who had served nine terms in the US House of Representatives after being governor of the state.

But in the general election, she turned a race that had looked winnable to many Republicans into a thumping victory for her Democratic opponent, Chris Coons, who won by 57 per cent to 40 per cent.

The defeat, blamed by some on her Right-wing positions on social issues alienating independent voters, also came at the end of a campaign that lurched from one public relations disaster to the next.

Bill Maher, a Left-wing television host, dug out footage of Miss O'Donnell on his show in 1999 saying that she had "dabbled into witchcraft". The remark received widespread media attention.

Attempting to defuse the situation, Miss O'Donnell filmed a campaign commercial in which she said down the camera: "I'm not a witch", but this only prompted further derision.

Serious questions were soon raised about Miss O'Donnell's education record, tax returns and handling of campaign funds. She denied any wrongdoing.

Then more footage emerged of Miss O'Donnell fronting an anti-masturbation campaign in the 1990s, when she publicly declared that she believed it to be "a sin".

Despite being classed, along with other Right-wing women politicians such as Sarah Palin, Michele Bachmann and Kristi Noem, as a "Mama Grizzly", she attempted to play down her views on such issues.

Ultimately, however, she alienated the relatively moderate voters of Delaware to such an extent that Mr Obama's Democrats avoided the loss of another seat in the Senate, of which they retained control.

Born in Philadelphia, Pennsylvania, in August 1969, Miss O'Donnell has said she grew up a liberal before becoming a born-again Christian while studying at Fairleigh Dickinson University.

She worked as a Republican campaigner in the 1990s before joining various anti-aborition and pro-creationist not-for-profit groups and becoming a television commentator.

She then set up her own media consultancy before making three attempts at the Delaware senate seat. In 2006 she finished third in the Republican primary. In 2008 she lost the general election to Mr Biden.

Her book 'Troublemaker: Let's Do What It Takes To Make America Great Again' has recently been published. She has declined to say whether she plans to run for office again.