Why is it that whenever I watch the show , the guests invariably have accents originating south of the Mason-Dixon Line ?
(I use the term MasonDixon colloquially , not its original meaning)
They don’t. The show is pretty much fiction. One example (that was repeated over and over on “Talk Soup” that comes to mind was a “couple” that came on. The “wife” complained about how her “husband” had a “girlfriend” and that they indulged in a vomiting fetish. The “husband” then complied by urping up a large quantity of flourescent green liquid on the “girlfriend”.
It just so happens that this particular “husband” was a performance artist (a regurgitationist).
A little more in-depth “analysis” of the matter: http://talkshows.about.com/library/weekly/aa020400a.htm
In short, the “guests” on Jerry Springer have the accents they have because Springer is of the opinion that these accents will play well to his target audience–urbanites and suburbanites who like to sit back and congratulate themselves on how superior they are to “those hicks”.
Was it Stevie Starr?
http://www.ukstars.co.uk/starr.htm
This guy has a pretty heavy accent
*A performance artist (a regurgitationist). *
Now there’s something to aspire to! I’ll bet your average career counselor is a little short on info, though. 
Well, Jerry Springer is pretty fake, but I have noticed a “white trash” drawl even in the North. I often hear it at Walmart. I don’t think that those people are performing for my benefit.
It could be that Walmart is a mecca for Southern transplants (while natives shop at the locally-based Target), but I don’t think that’s the whole story. The cashiers talk that way, too. It’s very strange.