The need for greater transparency regarding the income and overall financial dealings of candidates and their spouses was underscored by Mrs. Clinton’s recent decision to make a $5 million loan to her campaign. Such borrowing is a permitted practice under the campaign laws. But the campaign said the money came from her share of the Clintons’ joint resources, and that calls attention to the lack of information about their family finances. As a former president, Bill Clinton has been making millions annually giving speeches and traveling the globe. What is publicly known about his business dealings is sketchy, and clearer disclosure of them is required to reassure voters that Mrs. Clinton’s candidacy is unencumbered by hidden entanglements. 

In the same spirit, the Clintons are obliged to make prompt disclosure of the major donors who have been backing the former president’s library and foundation. It is not even clear whether Mr. Clinton would disclose his library’s donors if his wife won the White House.

Likewise, Senator McCain has yet to release his tax returns, a strange omission for a candidate with a record of supporting strong government ethics measures. A spokesman for Mr. McCain raises the prospect that he may hold back his tax returns through the fall campaign, saying that he would not decide whether to release them until he officially is the Republican nominee. That would neatly thwart the party-vetting process, even if he does finally make the returns public. In the meantime, questions are arising about the senator’s fund-raising as it relates to his position as the former chairman of the Senate Commerce Committee and its regulatory powers over business.