DES MOINES, Iowa (AP) — Gov. Terry Branstad says he’s considering a proposal that would let Iowa taxpayers decide if they want to deduct the federal taxes they pay from their state tax liability or just pay a lower flat state income tax rate. Branstad says discussions are in the early stages and models are being used to determine what the proposed flat tax rate might be. Currently, Iowa’s top marginal income tax rate is 8.9 percent, but ends up in the 6 percent range once federal taxes are deducted from a taxpayer’s state liability. Branstad says the proposal is part of a tax reform package for the 2013 legislative session on property and income taxes. He spoke about the plans on Tuesday to members of the Iowa Partnership for Economic Progress.