Key witness to testify against former Senator Edwards

The campaign aide who wrote a tell-all book about efforts to keep former Senator John Edwards' extramarital affair concealed during his 2008 presidential bid was expected to return to the stand Tuesday to testify against his former boss.

Andrew Young is the federal government's key witness in the criminal campaign finance case against Edwards, who failed to capture the Democratic presidential nomination. The former aide, who began testifying on Monday, was granted immunity.

Edwards, a two-time presidential hopeful who was the Democrats' vice presidential nominee in 2004, saw his star fall amid revelations that he cheated on his cancer-stricken wife and impregnated his mistress during the 2008 campaign.

He faces possible prison time if convicted of federal election law violations, including charges of conspiracy, accepting illegal campaign contributions and making false statements.

Prosecutors say Edwards, 58, manipulated Young into soliciting more than $900,000 from two wealthy donors to hide the affair and pregnancy and avoid destroying his campaign.

They say Young was so dedicated to Edwards that he agreed to falsely claim paternity of mistress Rielle Hunter's baby at Edwards' request.

But the former senator's defense on Monday said Young pocketed most of the money and used it to help bankroll a $1.5 million home for his family.

Young thought Edwards was his "ticket to the top," the defense said. When things soured, he recruited others to testify against Edwards in the criminal prosecution, according to the defense.

Defense attorneys said Young called three witnesses in the past two weeks to find out what they would say at the trial, behavior that is frowned upon but not illegal.

Prosecutor David Harbach acknowledged that Young and his wife mixed their money with the payments meant for Hunter and spent some of it on a new home.

On Monday, Young told jurors how he met Edwards during the U.S. Senate campaign and became his right-hand man for the two presidential bids.

Young has admitted that parts of his 2010 book about Edwards, "The Politician," are untruthful, Harbach said.

"You will not like him," Harbach told jurors. "But remember this: Mr. Young is an exhibit as much as he is a witness."