Not understanding nationalism

Via Hak there's a wonderful exchange between Tommy Sheridan and Gordon Brewer on Newsnight Scotland where Sheridan patiently explains why his support for Scottish independence doesn't mean he's a nationalist:

Brewer: Why are you a Scottish nationalist?

Sheridan: Why am I a Scottish nationalist?

Brewer: Yes.

Sheridan: I wasn't aware I was a Scottish nationalist...

Brewer: Well, you're calling for independence.

Sheridan: Yeah, em, a number of people are calling for independence - that doesn't make them Scottish nationalists.

He then goes on to describe his position - which is nationalist by most people's definition - then reiterates that it would be quite wrong to conclude that any of this makes him a nationalist. "You accused me of being a nationalist", he says to Gordon Brewer. He actually appeared to be mildly wounded by the suggestion.

Confused? Not as much as you're going to be if you watch the rest.