One thing to note reading through the Roll Call article, is that another notable Republican was able to speak about David Duke without putting on an asshat, that Republican being then state Rep but now Senator David Vitter, who won the Congressional race Duke had entered:

“I honestly think his 15 minutes of fame have come and gone,” said state Rep. David Vitter (R), a wealthy Metairie attorney who holds Duke’s old seat in the state House and is “seriously considering” a Congressional bid. “When he’s competed in a field with real conservatives, real Republicans, Duke has not done well at all.”

David Vitter’s got his own problems (the DC Madam scandal being the big one), but he’s not a hatemonger like David Duke and he knew how to give Duke the backhand.