Shelby's up for re-election next year, but would Chief Judge Moore want to be one of 100--and at the bottom of the totem pole to boot? Given how hidebound Senate rules are, he'd have difficulty being contained--and quiet. He is used to being Top Dog, and he'd definitely not be that for years in the Senate unless he intends to pull a Hillary and shove Sen. Sessions off the stage.
And, unless Riley is recalled, he's not up for re-election until 2006. Can Moore wait that long?
However, given Moore's national audience, I wonder, if he's removed by the Judicial Inquiry Commission, if he's going to do something else--speaking tours, writing, etc.