For most Americans, income tax returns are a private matter, and federal law protects that privacy. For those who would be president, a different standard applies.
The probing and investigating is a chance to examine all the ups and downs of a career, the critical moments and life experiences that might foretell how a president will make decisions.
This is why Mitt Romneys tax returns are important.
He has described himself as a successful capitalist who took risks and created wealth, a laudable credential. Voters would benefit by seeing and evaluating the details of that story, including through his tax records.
Romney does not need to go as far as his father, who made public 12 years of tax returns when he was running for president in 1968, but more than two years would be informative.
A president often has to decide how much to disclose about events or decisions that are not particularly pleasant. If Romney is not willing to open up his tax returns, what does that say about his instinct for leveling with the American people from the Oval Office?
On Tuesday, Romney brushed off demands to make public more tax returns, saying they would be used by the Obama campaigns opposition research.
But Romney surely is capable of responding to any distortions. For voters, the documents are essential exhibits in an application for the presidency. It is insulting to voters for Romney to keep them under wraps and will only fuel suspicions that he has something else to conceal. He should prove otherwise.