At that point, he knew that working for Mr. Edwards was all he wanted to do. He was drawn to the power and to the money.

“I thought it would lead to good things for my family,” he said.

Within the year, Mr. Young was spending his days doing whatever the Edwards family needed. He changed light bulbs at their home and changed the oil in their cars. He became Mr. Edwards’s driver, always making sure the senator had three newspapers, hand sanitizer and cold Sprite and wine at the ready…

Mr. Young said he went to increasingly elaborate lengths to help Mr. Edwards hide his relationship with Ms. Hunter. At one political event where both women were present, it was his job to keep them apart. In return, Mr. Edwards gave Mr. Young access to his business associates and helped him acquire some land so Mr. Young and his wife could build a dream house. Such was his devotion to Mr. Edwards that by the end of their relationship in 2008, Mr. Young would claim paternity of the child Mr. Edwards fathered with Ms. Hunter while running for president. “You said you actually fell in love with Mr. Edwards?” Abbe D. Lowell, Mr. Edwards’s lawyer, asked him at one point during last week’s testimony.