Buried at the bottom of the Associated Press's interview this week with Donald Trump is a quiet acknowledgement of something we've known for a long time: Trump has little intention of releasing his tax returns.

Trump "dismissed the idea that voters have a right to see his tax returns before going to the polls," the AP's Julie Pace and Jill Colvin write. "He's so far refused to release those documents, citing an ongoing audit. And besides, he said, 'there's nothing to learn from them.'"

A later article bumped that revelation up and added one other detail: Trump "has said he doesn't believe voters are interested."

It's worth contrasting those comments with what Trump said in January 2012, when then-Republican front-runner Mitt Romney was facing criticism for not releasing his taxes. Shortly before Romney did so, Trump appeared on "Fox and Friends" to suggest that Romney had no reason to hesitate. The clip, dug up by the liberal PAC American Bridge, quotes Trump as saying that he wouldn't hesitate to release his returns if he ran.

"Would that be a repellent for you, for Donald Trump, to reveal everything?" host Brian Kilmeade asks.

"No," Trump replies, "I actually think that it’s a great thing when you can show that you've been successful, and that you’ve made a lot of money, that you've employed a lot of people. I actually think that it's a positive."

In another interview, Trump criticizes Romney's fumbling answer to a debate question about releasing his taxes. "Mitt has to get those tax returns out," Trump said. "I'm a little surprised they weren't better prepared for that."

That was then.

This year, Trump has repeatedly insisted that because his tax filings are under audit, his lawyers are advising him not to release them to the public. We spoke with a tax attorney who agreed that it wasn't a great idea to take documents central to an investigation — which is what an audit is — and make them public.

That required taking Trump's word for the fact that the returns are under audit. So, last month, Trump released a letter indicating that returns from 2009 on are still under investigation. Investigations of returns from earlier years have been closed, but Trump's attorneys suggest that ongoing activities in documents being audited are "continuations of prior, closed examinations" in the sense that "transactions and activities" in earlier years were linked to things under audit. We asked former IRS commissioner Mark Everson to assess the claim that Trump therefore couldn't release his taxes; Everson (who at one time was a long-shot competitor to Trump in the GOP primaries) strongly disagreed.

Update: Romney, who has criticized Trump on this issue before, renewed his complaint on Facebook on Wednesday. "It is disqualifying for a modern-day presidential nominee to refuse to release tax returns to the voters," Romney wrote. Why? "[T]he potential for hidden inappropriate associations with foreign entities, criminal organizations, or other unsavory groups is simply too great a risk to ignore."

Everson also pointed out that there's a long history of candidates releasing tax returns — and of the release of those documents being used as political pressure points. During the Romney back-and-forth in 2012, CNN outlined the history of tax releases. CNN's Marlena Baldacci spoke with Joseph Thorndike of the Tax History Project, who linked the release of returns to the famous "Checkers" speech by Richard Nixon. That speech centered on allegations of financial impropriety by Nixon, who was then running as Dwight Eisenhower's vice president. Nixon outlined his financial history — including having been given a pet dog, Checkers, that he planned to keep — and called on his opponents to do the same.

I would suggest that under the circumstances both [Democratic vice presidential candidate John] Sparkman and [presidential candidate Adlai] Stevenson should come before the American people as I have and make a complete financial statement as to their financial history. And if they don’t, it will be an admission that they have something to hide. And I think that you will agree with me.

Shortly after he was reelected as president in 1972, Nixon was called on to release tax documents that were then under audit. (This was the "I am not a crook" incident.) He did.

The Tax History Project has a collection of past presidents' and past candidates' returns, from FDR through Mitt Romney to Hillary Clinton's. When Politifact looked at the history of tax return releases in presidential campaigns, it found that the tradition extended back to 1976. Every major-party candidate since 1972 has released returns with the exception of the Democratic candidate that year, George McGovern.

And it can be a point of leverage. In 1980, as Jimmy Carter was trying to fend off Ted Kennedy's challenge to his reelection nomination, a White House spokesman pivoted from questions about Carter's taxes to ones about Kennedy's. But it was Carter's general election opponent, Ronald Reagan, who was adamant about not obliging, saying that he would "make all disclosures required by law. I believe a bad precedent is indicated if we think anyone who is going to be in public life is going to make disclosures other citizens don't have to make. ... I feel this very strongly."

In August, he capitulated.

By August, Trump may do the same — though Trump's finances are of course much more intricate than were Reagan's. It's impossible to know what we might learn about Trump's business history by seeing what taxes he paid — or how much in taxes he actually paid — so it's hard to know whether or not Trump's insistence that "there's nothing to learn from them" is accurate.

For now, we'll have to take his word.