Hunter Biden's only qualification for obtaining a seat on the Amtrak board of directors in 2006 was that he often rode trains.

That's according to his father Joe Biden's Delaware colleague in the Senate, Tom Carper, who offered the sole nomination speech for the younger Biden when his name was presented in the Senate Commerce Committee. In his prepared remarks, Carper said Biden would be an "excellent addition" to the board, but was unable to list any reason beyond his frequent use of trains.

"More significantly, Hunter has spent a lot of time on Amtrak trains," Carper said after listing schools Biden attended. "Like his father, Rep. Mike Castle and myself, Hunter Biden has lived in Delaware while using Amtrak to commute to his job in Washington, D.C."

"You learn a lot about what works and what could work better at Amtrak by riding those trains," Carper said.

Rolling Stone‘s Matt Taibbi characterized Carper's nomination speech as a "sarcastic anti-recommendation."

Biden has used his position on the Amtrak board as justification for his high-dollar board seat on Ukrainian gas company Burisma. In an interview with ABC's Amy Robach that aired Tuesday, Biden said nobody buys the idea that he was unqualified for the Burisma job.

Asked by Robach what his qualifications for the job were, Biden said, "Well, I was vice chairman of the board of Amtrak for five years."

Biden elsewhere in the interview acknowledges that he would not have gotten either position if not for his father.

"I think that it is impossible for me to be on any of the boards I just mentioned without saying I'm the son of the vice president of the United States," he said. "I don't think that there's a lot of things that would have happened in my life if my last name wasn't Biden."