If he asked you to marry him?
I think its the same thing as can you marry any famous person or can you marry someone with a job that means that they are public property (e.g. a pastor or something). I think you'd have to be a really strong and self-assured person and have a very strong sense of self and a really solid relationship.
As to whether or not I can do it? I'd have to be in that relationship first to see whether it was worth the stress and the aggravation. I wouldn't necessarily seek it out, though.