So Mitt won't release his taxes, but he has someone look over the tax returns for him and provide summaries?
This sure brings to mind Nixon's attempt during Watergate to avoid turning over the White House tapes (the tapes that ultimately led to him resigning from office within days of their actual release), in the so called "Stennis compromise" that led to the Saurday Night Massacre.
From Wikipedia (edited): "After an initial refusal to comply on the grounds of executive privilege, Nixon offered to remit the tapes to a respected U.S. Senator, John C. Stennis, a Democrat from Mississippi. Sen. Stennis would listen to the tapes himself, then summarize the tapes for the special prosecutor's office. The explanation was that Stennis would be sensitive to matters of national security contained within, but it is believed that President Nixon did not want the tapes entered into the public record because they contained recordings of Nixon using coarse language and racial epithets, and - preeminently - implicating himself in the "cover-up" surrounding the Watergate break-in. Stennis was famously hard-of-hearing. Special Prosecutor Archibald Cox refused the compromise that evening. Nixon's response was to fire the special prosecutor the next day, in a chain of events later known as the "Saturday Night Massacre."
Special Note: Archibald Cox was my professor for a seminar at Boston University Law School. We took him to lunch one day and got lots of background on the players and interactions behind Watergate. He was a wonderful man, who used the force of moral authority (and some canny personal and political instincts) to play a pivotal role in that historic moment.