Republican vice presidential candidate Sarah Palin's colourful life story as an avid hunter and 'hockey mom' is quickly turning the little-known Alaska governor into a juicy target for late-night US television talk-show hosts.

Just days after Arizona Sen John McCain tapped her as his surprise running mate, the shows were poking fun at her complicated family life.

Mrs Palin's 17-year-old unmarried daughter is pregnant, and the governor is under investigation for firing an underling who refused to dismiss a state trooper going through a messy divorce from Palin's sister.

'The Palin family crisis that we were talking about on Sunday and Monday ... has been solved now, and today the baby is being adopted by Angelina Jolie,' CBS Late Show host David Letterman deadpanned on Tuesday.

The sheer volume and pace of disclosures about Mrs Palin have been like catnip to comedians, many of whom have complained that Democratic nominee Barack Obama has proven relatively goof-proof.

Mrs Palin offers a rich melange of fresh material just when age jokes about Mr Obama's Republican rival, McCain - who at 72 would be the oldest first-term US president - are starting to wear thin.

'You could get a vaudevillian troupe, and they could do two hours of stuff that's already been written and circulated about her,' said Robert Thompson, a media and pop culture scholar at Syracuse University.

Guns, experience, family
Much of the humour is drawn from Mrs Palin's passion for guns, moose hunting, limited experience in public office and large and growing family - all in a state viewed as a bastion of idiosyncrasy.

Thompson said Mrs Palin was attractive to comedians because of her hero status among social conservatives who just months ago decried the teenage pregnancy of Jamie Lynn Spears, sister of pop star Britney Spears, as setting a bad example for girls.

Jay Leno, star of NBC's The Tonight Show, put his spin on Mrs Palin's daughter's pregnancy, joking: 'Apparently she told Mr McCain about this a week ago, but what happened was she said it into his bad ear.'

The many facets of Mrs Palin's predicament set her apart from others in the pantheon of modern political punchlines, such as Idaho Sen Larry Craig's restroom scandal, Mr John Edwards' extramarital affair and Vice-President Dick Cheney's hunting accident.

'Another vice president who's a hunter. What could go wrong there?' Leno joked.

The last time a major-party vice-presidential pick was so heartily lampooned was when Mr Dan Quayle, a young Indiana senator, was named as President George H.W. Bush's running mate in 1988.

Mr Quayle was widely spoofed as a political light-weight with a 'deer-in-the-headlights' look, but they went on to win the election by a healthy margin. -- REUTERS