It’s no wonder Americans have a negative opinion of both major presidential nominees. Beyond their escalating rhetoric, both Hillary Clinton and Donald Trump continue to act as if they have something to hide, raising the prospect that voters may not know everything they should before Election Day.

Investigators keep finding more Clinton-related emails, underscoring the former secretary of state’s lack of transparency and her cozy, continuing relationship with the Clinton Foundation and its donors (though so far one that more exemplifies traditional Washington access of contributors than indicates improper impact on governmental policy).

And Trump continues his refusal to follow tradition and release his tax returns, enabling him to keep many details of his complex finances from public view. Investigative reporting by authors and newspapers suggests everything from a history of housing discrimination to potentially serious conflicts involving major banks and foreign countries.

Two separate events in the past week illustrated both their respective problems and the significant contrast between what we know of the one and the other.

One was The Associated Press revelation that Clinton’s appointment calendars, obtained through a Freedom of Information Act lawsuit, showed dozens of private meetings while she was secretary of state with foundation contributors. Clinton tried to keep the data secret, both by setting up her private email system and rejecting AP requests. But the AP found no ethical or legal violations.

The other was a bizarre interview with Trump’s doctor about his letter declaring the Republican nominee would be “the healthiest individual ever elected to the presidency.”

Dr. Harold Bornstein told NBC News he wrote the letter, largely devoid of specifics, in just five minutes while a representative of the candidate waited in his limousine outside, adding, “I think I picked up his kind of language and then just interpreted it to my own.”

Both the minimal content and the circumstances Dr. Bornstein related seemed surprising from a candidate whose campaign repeatedly suggests — without any evidence — that Clinton is covering up details about her health. In fact, while Clinton has also not issued full medical details, she has provided more than Trump, which has not prevented him from pledging now to reveal his details if she disclosed hers.

That contrast in transparency seems generally to be the case. Though Clinton has often limited her disclosures, and continues to avoid full-scale press conferences, Trump has done less.

Their tax returns are the main example. Clinton and her husband, former President Bill Clinton, have followed the traditional approach for presidential nominees by releasing returns for 30 years, at the cost of stories about their vast income from speaking fees and other outside endeavors. Trump has refused to release his tax returns, citing the fact that recent years are under audit.

His son Eric said it would be “foolish” to release prior returns, because, “You would have a bunch of people who know nothing about taxes trying to look through and trying to come up with assumptions on something they know nothing about.” Indeed, there is little doubt journalists would find fertile ground; the few years for which Trump was forced to release earlier returns showed he paid no taxes.

But more significant than his tax rate might be any internal evidence of financial indebtedness to foreign countries that might influence his actions as president.

An extensive study by The New York Times into Trump’s real estate holdings showed his companies owed at least $650 million to institutions including the Bank of China, one of the largest state-owned banks in the country against which he has threatened a trade war, and Goldman Sachs, the firm whose large speaking fees to Clinton he assailed.

At a 2008 real estate conference, Donald Trump Jr. disclosed his father had substantial interests in Russia, whose leader and policies Trump praised, while indicating he would be friendlier than Clinton. “Russians make up a pretty disproportionate cross-section of a lot of our assets,” according to an account on eTurboNews’ website.

Disclosure of financial holdings — and debt — from countries like China and Russia would seem at least as important as seeking meetings for contributors who include some foreign leaders.

The American people deserve full disclosure from both: The State Department should speed its release of Clinton’s emails, and the Clintons should take steps to separate themselves from the foundation’s management now.

Both should release detailed reports on their health. Trump should release his tax returns. And Clinton should expand her press interactions to include regular opportunities for questioning by her traveling press corps.

Voters deserve nothing less.

Carl P. Leubsdorf is a columnist for The Dallas Morning News. Readers may email him at carl.p.leubsdorf@gmail.com.