"That makes no sense." (Your type of posting is fun!)
There is no helping Zel he has retired, and as a wedge into southern dems he is very useful in deprogramming them. I for one see no drawback in having him speak at the convention, and as for ideological purity-compared to (R)nold and McCain and Rudy, he's the most conservative. "So what is your point?"
I question why Zell Miller would be invited to speak and not someone like Alan Keyes. Keyes is more conservative than HE is.