Who's Who in the John Edwards Trial In 2008, John Edwards was in the midst of his second presidential run when rumors surfaced that he was having an affair with campaign videographer Rielle Hunter. As pressure mounted on the campaign, a pregnant Hunter went into hiding with Edwards' trusted aide Andrew Young, and his family. Young initially claimed he was the father of the child but he eventually turned on Edwards and wrote a scathing tell-all book about the ordeal. Now the disgraced ex-North Carolina senator faces felony charges that he misused campaign funds from two wealthy donors to pay off Hunter and Young, kept them in hiding, and flew them in private jets to keep the affair and the child a secret. After two delays and a failed plea bargain negotiation, opening arguments began Monday. Many will be watching to find out Edwards' fate; he is facing up to 30 years in prison and a $1.5 million fine. Here are some of the key players in the case. John Edwards Once a darling of the Democratic Party, John Edwards has fallen far since his failed run for president in 2008. A former senator, vice presidential nominee and two-time presidential candidate, Edwards saw his campaign fall apart when revelations about his affair surfaced. Edwards initially denied the rumors before coming clean to ABC News' Bob Woodruff, calling his affair with Hunter a "very serious mistake" and claiming it ended in 2006. The claim was later proven false when Edwards admitted he was the father of Hunter's daughter, who was born in 2008. Edwards now stands accused of illegally using campaign funds to cover up the affair by paying off Hunter and Young. Edwards denied knowing about the payments, a statement he has stood by since the 2008 "Nightline" interview in which he told ABC News' Bob Woodruff, "I never asked anybody to pay a dime of money. Never been told any money's been paid. It's an absolute lie. The extent to which Edwards knew about the payments is a crucial element in this case. Andrew Young Once a close friend and aide to Edwards, Young has emerged as Edwards' chief adversary in the trial. Young, who has received immunity in exchange for serving as the prosecution's star witness, initially claimed paternity of Rielle Hunter's child. When revelations of the affair surfaced, Young, a married father of three, went into hiding, moving to California with his family -- and Hunter, allegedly at the expense of the Edwards campaign. Young further elaborated on the events in a book, "The Politician: An Insider's Account of John Edwards's Pursuit of the Presidency and the Scandal That Brought Him Down." In the book, Young accused Edwards of masterminding an elaborate cover-up, using campaign money to finance a scheme in which Young would claim paternity for the child that Edwards knew was his. Although Young later admitted to falsifying parts of the book, Edwards also claimed paternity of the child, leaving both men with questionable credibility. Young told "20/20" that it cost Edwards' benefactors' $1 million in cash, private jets and hotel rooms to cover up the affair and Hunter's pregnancy. It Edwards' knowledge of how this money was spent, that will be at the center of the case. Rielle Hunter Hunter, a videographer and producer, was working for the campaign, creating a series of short videos, when the affair occurred. As allegations of the relationship surfaced, Hunter -- then pregnant with Edwards' child -- went into hiding in California where she gave birth to a daughter, Frances Quinn Hunter. Although Young claimed paternity of the child at the time, she did not list a father on the girl's birth certificate. Edwards' has since claimed paternity of the child. This isn't the first time that circumstances related to the sex scandal have brought Hunter to the courtroom. In 2010, she sued the Young family, claiming the couple had stolen a "personal and private" videotape from her. The tape, which came to be known in court filings as "the Edwards sex tape," was ultimately destroyed after the two sides reached an out-of-court settlement. Hunter and Edwards still see each other during visits with their daughter, now 4. Some sources indicate that the relationship between Edwards and Hunter has cooled considerably as of late, allegations which Hunter's publicist has denied. Frederick Baron A prominent Democratic fundraiser and wealthy Texas trial lawyer, Frederick Baron served as the campaign finance chairman of Edwards' 2004 presidential campaign. Baron made his fortune suing large chemical companies and asbestos makers on behalf of those contaminated by their products. Baron passed away from blood cancer in 2008, but not before admitting to paying off Hunter and Young to hide the pregnancy from the public eye and to move to California. He claimed that John Edwards had no knowledge of the pay-offs. Rachel Lambert "Bunny" Mellon Reclusive heiress to a banking fortune, Rachel Lambert Mellon is the last person many would expect to be tied up in a torrid sex scandal. Mellon first became enamored with Edwards, who she said reminded her of President John F. Kennedy, during his 2004 Presidential run. Mellon gave hundreds of thousands of dollars in gifts to Edwards, money later spent to help keep Hunter and Young in hiding in order to keep the scandal out of the public eye. Mellon, who at 101 years of age is too ill to travel, is not expected to testify at the trial, however, her lawyer, Alex Forger, will be testifying on her behalf. Wendy Button A longtime speech writer for John Edwards, Wendy Button was recently ordered to turn over any drafts of books or articles involving Edwards and other key players in his case. Button, who denied having any knowledge of the affair and subsequent cover-up during the campaign, has appeared on potential witness lists for both the prosecution and defense. She is expected to testify about her actions in the aftermath of the scandal, during which she advised Edwards on how to best admit he lied to the American people, and she helped draft the 2009 statement in which he publicly acknowledged his affair. Cate Edwards The eldest of the Edwards children, 30-year-old Cate Edwards may be her father's saving grace. Cate is a graduate of Harvard Law and was seen whispering legal advice into her father's ear during jury selection and opening statements, according to the Huffington Post. She has been heavily involved in her father's case ? his attorneys consulted her several times during jury selection -- and she may be called to testify on her father's behalf. Judge Catherine C. Eagles Presiding over the case is Judge Catherine C. Eagles. Appointed by President Obama in 2010, this will be among the higher-profile cases Eagles has tried since her appointment to the bench. Early in 2012, Eagles made the decision to delay the trial to allow Edwards to undergo an operation. The trial had previously been delayed due to Edwards' desire to attend his daughter's wedding. Eagles defended these decisions saying, "The public has an interest in a speedy trial. Ordinarily, I would try to manage something like this. But clearly there are some limitations on Mr. Edwards due to real and serious health issues. Elizabeth Edwards Although she passed away after battling metastatic cancer, the spirit of Elizabeth Edwards will undoubtedly cast a long shadow over the trial. John Edwards' wife, as well as a chief policy adviser on the campaign trail, she was suffering from cancer at the time of the affair. Initially, Elizabeth Edwards stayed with her husband after he admitted his infidelity, but she went on to legally separate from him after he acknowledged paternity of Hunter's daughter. A popular figure, health care advocate, and author of two best-selling books, the circumstances surrounding her death will most likely reflect negatively on John Edwards in the minds of jurors.