Mike Segar / Reuters
And in not doing so, he's setting a precedent for secrecy that others will likely follow.
It's a tradition that has been followed by every U.S Presidential candidate for 40 years.
One prominent backer noted that the GOP nominee has said multiple times that he'd make the documents public.
BRENDAN SMIALOWSKI via Getty Images
"It has nothing to do with Russia," campaign chairman Paul Manafort said.
Jim Urquhart / Reuters
"Maybe I'm going to do the tax returns when Obama does his birth certificate," he said in 2011.
No stranger to questions about his taxes and wealth, former GOP presidential nominee Mitt Romney on Wednesday criticized Donald Trump's decision to withhold his tax returns from the public, calling th...