Yet it has become a given that nominees, much like presidents and vice presidents, release their income tax returns. Texas Gov. Rick Perry (R) has released his, and former House speaker Newt Gingrich (R) pledged he would do so upon becoming the nominee. As with bundlers, Mr. Romney hides behind legal requirements. It is true that candidates are required to file financial disclosure forms, but tax returns provide information not otherwise available, including charitable contributions and effective tax rates.

During Mr. Romney’s 1994 bid to unseat Sen. Edward M. Kennedy (D-Mass.), he called on the senator to release his tax returns to prove he had “nothing to hide.” Yet Mr. Romney did not release his own returns during that campaign or his subsequent run for, and service as, governor. Would a President Romney release his tax returns? We posed that question to his campaign, twice, and did not receive an answer.