Mitchell Zuckoff writes: Lost in the debate over Donald J. Trump’s refusal to release his tax returns is the story of where the custom of disclosure comes from — and why it can be so valuable as a measure of character. It’s a tale of presidential tax shenanigans, political scandal and one of the most famous quotations in American history: Richard M. Nixon’s “I am not a crook.”

The story begins in July 1969, when Congress eliminated a provision of the tax code that had allowed a sitting or former president to donate his papers to a public or nonprofit archive in exchange for a very large tax deduction. Congress’s rationale was that a president’s papers already belonged to the public.

In his taxes for 1969, President Nixon indicated that four months before Congress acted, he had donated more than 1,000 boxes of documents to the National Archives. He claimed a deduction of more than $500,000. [Continue reading…]