Transparency is not the natural instinct of the politician. The political mind tends to think: What voters don’t know can’t hurt me. What political opponents, and media, do with information can.

So the ordinary urge is to hold close, to dribble out, to yield the bare minimum, unless the politician perceives some comparative advantage in revelation. (Think Jeb Bush, eye on Hillary Clinton, unloading years of gubernatorial emails, plus a gusher of tax returns.) The role of the media should be to counter this impulse toward secrecy, demand disclosure and — in appropriate circumstances and appropriate ways — inflict pain on candidates who resist.

Such as this column.

The current campaign features two parallel arguments over transparency — on the Republican side, Donald Trump’s tax returns; on the Democratic side, transcripts of Clinton’s paid speeches.

The two issues are not equivalent, in that releasing tax returns has been a standard rite of presidential candidacy for decades. According to tax historian Joseph Thorndike, a contributing editor for Tax Analysts, every major-party nominee since 1980 has done so.

Clinton’s speeches, by contrast, present a question of first impression. She is not going against the grain of common practice so much as balking at broadening the definition of what material ought to be available to the public when it comes to presidential contenders.

Still, both candidates are resisting disclosure. Both are wrong. And both are revealing a troubling attitude that can only be expected to persist and worsen in the White House.

Trump once expressed willingness to release his taxes. “I have no objection to certainly showing tax returns,” he told radio host Hugh Hewitt last February.

Now, Trump is hedging. “I will absolutely give my return, but I’m being audited now for two or three years, so I can’t do it until the audit is finished, obviously,” he said at Thursday’s CNN-Telemundo debate. “And I think people would understand that.”

Um, no. First, Trump’s audit excuse would not stop him from releasing tax returns covering previous years. Second, whether to release tax returns for years still being reviewed is entirely within Trump’s discretion; he’s the boss of his own returns. Sure, no prudent tax lawyer would be thrilled about a client making audited returns public. Tough.

“We ask a lot of candidates that normal people wouldn’t do,” Thorndike told me. “I’m sure it will be inconvenient while he’s under audit, and his lawyers are probably aghast at the prospect of that, but I don’t think that’s really relevant in this situation.” Indeed, would President Trump resist releasing tax returns because he was being audited?

This information matters. “You don’t learn anything about somebody’s wealth with a tax return,” Trump claimed at the debate, but size isn’t the only relevant factor here. Tax filings allow voters to know what effective tax rates candidates pay and how aggressively they have used loopholes in the code. They provide details on how much candidates have donated to charity and to what organizations. This information might not be dispositive to choosing a candidate, but it is instructive.

Clinton’s speeches are different in that we don’t know what’s there or not, which is precisely the point. Clinton’s stance has evolved from ducking (“I will look into it”) to brushing off (“happy to do it when everybody, including the Republicans, does it”).

Wrong. Wrong. Wrong. Clinton is running in a Democratic primary, against a candidate who has made her ties to Wall Street bankers an issue. Clinton argues that what she said in private doesn’t matter because “I have a record. I’m not coming to this for the first time.”

This has things backward. Yes, Clinton has a public record. But for voters worried about whether she would be tough enough on bankers, it seems reasonable for them to wonder: What did she say to them behind closed doors, at $225,000 a pop?

Most important, transparency is not, or shouldn’t be, situational. Clinton has made tax returns public without Trump having released his. Why should it matter what Republican candidates do? Either it’s reasonable to ask for disclosure or it isn’t — although if there are Trump speech transcripts out there, by all means let’s see those, too.

Voters beware. How politicians behave on the campaign trail offers a window into what they will do in office. Candidates lacking in transparency before Election Day aren’t inclined to improve once they win.

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