"I think Isakson has caved in to the pressure of the fair tax and is worried because it has so much support in Georgia and he isn't a co-sponsor."
As others have pointed out, Isakson is under the thumb of some very wealthy real estate investors. I met with Robert LaMutte, who was running for the seat that Johnny vacated, which was ultimately won by Tom Price. He told me that these guys had told him not to support the FairTax for any reason. LaMutte was not as beholden to them as Johnny and he supported it anyway.
This is nothing more than an attempt to delay and placate those who want real tax reform. It is also precisely the position he held three years ago. Isakson supports the FairTax only during political campaigns.
I didn't pay much attention to Isakson after Cain lost. So some of this (not all of it) is news to me. We'll see what happens. I'll make this promise, if he is leading us all down the primrose path I'll be on him like ticks on a deer.