Richard C. Hoagland: Astronomer, Pseudo-Scientist or Entertainer?

We listen to a radio show called Coast To Coast AM that has a frequent guest named Richard C. Hoagland. He is billed as the show's science advisor and is very articulate and interesting to listen to, particularly when he is talking about astronomy and space. My boyfriend thinks he is a latter-day scientific snake oil salesman: Is he correct in his opinion?