"What is your tax rate?" George Stephanopoulos asked Donald Trump on ABC's "Good Morning America."
"It's none of your business," Trump replied.
That answer is absolutely and completely unacceptable. When you choose to run for president, and have a real chance of actually winning, everything becomes the public's business.
This principle goes far beyond Trump's taxes. If voters are going to make a reasonable judgment about how he might act in the future, they have a right to know how he's acted in the past. Everything means everything. Transparency and accountability are not optional.
This principle applies to all candidates, including Hillary Clinton, but it is particularly important in Trump's case because he has never held public office. He has never been through an election, or even a congressional hearing -- experiences that test and expose a person's background and ability to perform under pressure.
He has never served in a legislature, so he has never had to cast a single vote that forced him to go beyond speechifying and crystalize how he truly feels about an issue. He has never been an executive -- meaning a mayor or a governor -- where he had to make decisions that reveal his core values and priorities.
Clinton, by contrast, has run three major election campaigns -- twice for the Senate, once for president, not including her current bid -- and been confirmed as secretary of state by a vote of 94 to 2. She's cast thousands of votes and made numerous appearances before congressional hearings, the latest in October, when she answered questions about Benghazi from hostile Republicans for almost 11 hours.
Republicans are demanding even more information: about her use of a private email server during her State Department tenure; about what she knew and said during the violence in Libya that cost three American lives in 2012; about the paid speeches she made after she left office.
So Trump and his allies set new standards for hypocrisy when they defend his refusal to reveal his taxes. One of the worst has been Reince Priebus, the chairman of the Republican National Committee, who made this ridiculous statement on ABC: "Donald Trump represents such a massive change to how things are done in Washington that people don't look at ... whether or not he releases his taxes."
It's precisely because Trump represents "massive change" that the demand for disclosure is non-negotiable. And it's totally irrelevant whether his core supporters care about the Dear Leader's taxes.
Devoted Trumpians will not decide the election. But for swing voters in swing states, who have not yet chosen a candidate, that information is essential. So is a stream of stories that are just starting to fill in other blanks in Trump's past.
The New York Times documented the history of Trump's degrading and demeaning attitudes toward women. The Washington Post revealed that he frequently called reporters and lied about his true identity. The Wall Street Journal calculated that his tax proposals would "dramatically raise the debt, not decrease it, much less produce a surplus."
Trump's tax statements represent a particularly critical piece of information. As the Journal put it, "If Mr. Trump refuses to release his returns until after the election, that would make him the first major-party nominee since President Gerald Ford in 1976 to not release even one year of his actual returns."
Moreover, Trump is selling himself to voters as a highly successful businessman and deal-maker. His own boasts only boost the relevance of his financial records.
In defending his stonewalling, Trump told the Associated Press that "there's nothing to learn" from his returns.
That is, to put it charitably, a total untruth.
The Fact Checker column in the Washington Post listed at least five important items the returns would reveal: Trump's annual income; the sources of that income; how much he gives to charity; how aggressively he's tried to avoid taxes; and what rate he actually pays.
"Trump falsely claims that voters would learn nothing from his tax returns," the Post concluded. "To the contrary, voters would learn a lot of information that Trump has long tried to hide from the public. Tax returns would help lift a veil of secrecy about Trump's finances -- and let voters know whether his claims about his wealth and charitable giving are true, or if he's just a bombastic man behind the curtain akin to the Wizard of Oz."
Trump's refusal to reveal his taxes shows utter contempt for the voters and the democratic process. The voters should show him contempt in return.