Looking at Romney’s record for the Presidential White Paper series, the Club for Growth noted Romney’s opposition to the flat tax specifically…

But in Plymouth, N.H., today, Romney made a statement that suggested he might be changing his position. “The proposals that I’ll be putting out this fall will talk about bringing our tax rates down, both at the corporate level and the individual level, simplifying the tax codes, perhaps with fewer brackets. The idea of one bracket alone would be even better in some respects,” Romney said.