Conservatives are eager to see Marco Rubio win in Florida’s Senate race and Tim Burns win in the special election to replace the late Rep. Jack Murtha (D., Penn.). In both cases the candidates have faced an obstacle: past comments friendly to the FairTax. In both cases the candidates have responded by backing away from the proposal. There are differences between these cases: Burns’s initial statement was pretty qualified, and the Democrats have distorted what he said. But the lesson these conservative candidates seem to have drawn is that the FairTax is politically toxic. I think it is hard to look at either race and argue that the candidates would be doing as well as they are if they had stood behind the FairTax idea.