At the moment it is not legally mandatory for Representatives, Senators, and Presidents's to release their income tax forms.
By having them release their income tax records the People can see if there state representatives benefit or not from the very laws they enact that address taxes and deductions, etc.
A more transparent government will allow the People to see if its elected government is representing the People or for the benefits of the elected officials.
During the past election, 2012, Romney was hard pressured to release his. He said he would release 2 years, 2010 and 2011, but no more. Nancy Pelosi hard pressed this during the race but wouldn't even release her income tax forms.
This should be made for all elected officials to release their forms for the past ten years.