http://www.mscode.com/free/statutes/23/015/0855.htm
This is the link Deport provided that appears to be the law on the subject (Oregon, TX, and PA are recent states that had special elections for resigning Senators). From glancing at it, it looks to me like there would have to be a special. But I will read it more carefully later. Deport, what does it look like to you? When would there be an election to replace Lott?
"Shortly after Lott spoke, more than 20 of them participated in a telephone conference call to discuss the fallout. Lott was not present."
So however Lott delivered the threat it wasn't in that conference call.