If he was guilty of tax fraud, the IRS would've been on top of it a long time ago. We all know the tax code is messed up, but you don't need HIS tax returns to prove it. He just got into politics, so HE did not write the tax codes, he just followed them, like EVERY OTHER BUSINESS AND PERSON!
Do you get the earned income credit? What about the additional child tax CREDIT? Do you take any deductions?
The simple fact is his tax return would not show any wrong doing on his part.