Republican presidential candidate Donald Trump speaks during a campaign stop at the Palladium at the Center for the Performing Arts on May 2, 2016 in Carmel, Ind.
Photo by Joe Raedle/Getty

Clinton campaign keeps up pressure on Trump over taxes

Sensing an opening, Democrats are digging in on Donald Trump’s refusal to release his tax returns before the election.

MSNBC Live, 5/14/16, 1:37 PM ET

Donald Trump’s taxes- Do they really matter to the public?

Current presidential candidate for the libertarian party Gary Johnson talks the possibility of a third party candidate and Donald Trump’s tax returns-is it any of our business?
Current presidential candidate for the libertarian party Gary Johnson talks the possibility of a third party candidate and Donald Trump’s tax returns-is it any of our business?
The Hillary Clinton campaign, looking to keep up the pressure, emailed supporters a petition on Tuesday calling on Trump to disclose the material. 

“What is he so afraid of us finding?” the email reads. “It’s time for him to play by the rules and release his tax returns. If you agree, add your name now.” 

Last week, Clinton’s team released a video entitled “What’s Donald Trump Hiding?” that focused on the tax issue. She also discussed the issue herself at a rally after a voter shouted out a remark about Trump’s returns.                                

Trump indicated last year that he would release his tax returns as a candidate, which every major party nominee over the last four decades has done, but backed away later during the primaries. Last week, he told the Associated Press there was “nothing to learn” from his taxes, and that he probably would not release them before November due to an ongoing audit, although the IRS has confirmed there’s nothing legally preventing him from doing so.

“Mr. Trump is undergoing a routine audit,” Trump spokeswoman Hope Hicks said in an email. 

RELATED: Trump on his tax rate: ‘None of your business’

Democrats see the tax issues as a sword that cuts Trump in multiple ways. On one hand, Trump’s ongoing refusal to put to rest questions about his returns is inviting a free-for-all of speculation about what he might like to keep secret – speculation that Democrats are happy to encourage. 

“You’ve got to ask yourself, why doesn’t he want to release them?” Clinton asked supporters last week. “Yeah, well, we’re going to find out.” 

In the absence of his returns, Trump has also had to bat away smaller stories about individual items gleaned from other sources. This week, ABC News noted that Trump had claimed a golf course he owned was worth $50 million in a candidate disclosure form, but his attorneys claimed it was worth only $1.35 million for local property tax purposes, a massive gap that would save him large amounts. Trump’s attorneys subsequently revised their estimate to $9 million. 

But the bigger impact if Trump releases his taxes might not be details of his deductions, but how it dovetails with a related Democratic line of attack over Trump’s tax policy. 

RELATED: Trump camp doubles down on outlandish tax plan

While Trump has waffled on his tax position somewhat, he released a detailed white paper describing what the non-partisan Tax Policy Center estimates is a $9.5 trillion tax cut that would dramatically slash taxes for the rich. His campaign appears to be sticking by it. If Trump were to release his returns, it would enable Democrats to highlight his own tax rate, calculate his savings from his plan and incorporate them into attack ads undercutting his populist brand. Clinton is running on raising taxes on the wealthy to fund new benefits for workers, like paid leave.  

While Trump has cited the audit as the reason he won’t release his taxes, he also got testy when asked on ABC’s “Good Morning America” about his tax rate.

“It’s none of your business,” he said, adding that he “fight[s] very hard to pay as little tax as possible.”

The Wall Street Journal estimated Trump’s 2016 income at $160 million using a variety of sources, but tax experts told MSNBC that without more details about his deductions and how he classified his income, it was impossible to estimate his tax rate.

RELATED: Why Trump needs women voters if he wants to win

In the meantime, Clinton has made Trump’s tax plan a focus of her early attacks, saying it was “written by a billionaire for billionaires” in speeches on the trail.

Former GOP nominee Mitt Romney, who Democrats hit hard over his own tax disclosures in 2012, has also needled Trump over the issue.

“It is disqualifying for a modern-day presidential nominee to refuse to release tax returns to the voters,” Romney said in a Facebook post last week.