Dan Janison Melville. N.Y. Tuesday January 26, 2010. Daniel Janison,

Dan Janison has been a reporter at Newsday since 1997.

For 40 years, major-party presidential candidates have released tax returns. Though not legally required, it became accepted practice after Watergate, when elected officials were under pressure to show they were not crooks.

The latest Republican nominee-in-waiting, Donald Trump, has so far refused to release his filings. He said Tuesday there’s “nothing to learn from them” and he doesn’t believe voters are interested, but he clearly doesn’t want to let the people be the judge of that.

This is not a sudden issue. In February 2015, he said in a televised interview, “I would release tax returns” if a candidate. In March of this year, he released a letter from tax attorneys saying an IRS audit for 2009 and after is continuing.

That is a dodge, since no law keeps him from releasing the forms as they are now filed.

By contrast, Democrat Hillary Clinton’s campaign website has links to her and husband Bill Clinton’s tax returns for 2007 through 2014. She’s been pounding on her primary rival Bernie Sanders for his own holding back so far on income taxes.

Clinton, on the other hand, has yet to come across on Sanders’ demands she release transcripts of high-paid speeches she made to Goldman Sachs.

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Expect Trump to join in on that, but for now, Clinton has the offensive edge. At a rally in New Jersey, she said of her likely opponent and his income taxes: “You’ve got to ask yourself, why doesn’t he want to release them?”

“Yeah, well, we’re going to find out,” she said, with a bit of “you-haven’t-seen-nothing-yet” suggestion.

Trump told The Associated Press Tuesday he’d release the returns only after the audit ends — which wasn’t expected to be until after the November election. On Wednesday, Trump told Fox News, “Hopefully before the election, I’ll release.”

That further muddied the issue.

This week Bloomberg View journalist Timothy O’Brien wrote about how he’s seen Trump’s tax forms — obtained “as part of a legal action in which he sued me for libel (the suit was later dismissed).”

But the records were sealed, and “a court order prevents me from speaking or writing about the specifics of what I saw,” O’Brien said.

Still, he hinted of interesting things to be found if the forms are disclosed.

For one thing, they could help Trump clear up suspicions raised in other disclosures that he overstates his financial success.

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For another, he has criticized other companies for sending jobs overseas. Disclosing his taxes could give a sense of how the scope of his own global operations, O’Brien said.

And forms going back a few years could reveal the extent of his charitable giving.

People also would know if Trump lists any tax havens or shell companies.

Ex-Mayor Michael Bloomberg, Trump’s fellow former Democrat-turned-Republican New York billionaire, made waves during his first campaign in 2001 when he refused to release tax forms.

Told his opponents had done so, he said: “Yeah, well, they don’t make anything.”

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Unlike Trump, who’s worth less than the ex-mayor, Bloomberg was actually known to lowball his net worth.

During his tenure, Bloomberg did give reporters a once-a-year look at redacted versions of his tax forms, along with required city disclosure forms.

The political bottom line: Bloomberg was elected three times.