"If he starts screwing around with the tax code you have two issues. One is conflicts of interest: Because he's in the real estate business we know from the 1995 tax return he has a huge tax loss carried forward even though he probably didn't lose any money. And then we have in 2015 a vested interest in this debate over the alternative minimum tax," Painter said, pointing out that without that loophole Trump would have paid at least $2 million more in taxes.