HEMPSTEAD, New York -- Donald Trump slammed Hillary Clinton on trade at the start of the first presidential debate, hammering away at a policy area that has both haunted Clinton and helped Trump's brand during the 2016 campaign.
As the candidates discussed their respective economic plans, Trump blamed former President Bill Clinton for signing NAFTA, referring to it as the "worst thing that ever happened to the manufacturing industry." Then, Trump went after Clinton herself on a key vulnerability: "And now you want to approve (the) Trans-Pacific Partnership."
The exchange over the massive trade deal, which involved the candidates talking over each other and hurling accusations, was one of the most explosive of the evening and marked the spirited return of a political issue that was a prominent feature of the primary season.
Trump noted that Clinton had once favored the trade pact before coming out against it.
"That is just not accurate," Clinton shot back. "I was against it once it was fully negotiated and the terms were laid out."
"You called it the gold standard. You called it the gold standard of trade deals," Trump said, recalling a description Clinton once used while the trade deal was being negotiated.
"Donald, I know you live in your own reality but that is not the facts," Clinton said -- a jab alluding to Trump's past involvement in reality TV. "I said I hoped it would be a good deal ... I concluded it wasn't."
Trump cut in to ask multiple times: "So it is President Obama's fault?"
Clinton was criticized for flip-flopping on her past support for TPP throughout the primaries when she ran against liberal Vermont Sen. Bernie Sanders.
She came out against the deal after she started running for president and as she faced pressure from progressives to oppose what many Americans fear would take jobs away from the United States.
Trump, meanwhile, has been very vocal during this election in his opposition of TPP -- a position that has helped the businessman boost his populist economic message and win over working-class voters.
Trade wasn't the only topic that made the two nominees testy, however.
When NBC's Lester Holt, the debate moderator, brought up the issue of Trump's tax returns, the billionaire gave his usual answer: that his tax returns are current under audit. He said that he would release his tax returns if Clinton "releases her 33,000 emails that have been deleted."
Clinton kept the emails on a private server she used as secretary of state that was later destroyed.
She jumped at the opportunity to slam her opponent for refusing to release his taxes, something that has been customary for presidential nominees for years.
"You've got to ask yourself: Why won't he release his tax returns?" Clinton said, suggesting that Trump may not be as wealthy or charitable as he claims. "Or maybe he doesn't want the American people, all of you watching tonight, to know that he's paid nothing in federal taxes."
"There's something he's hiding!" Clinton alleged.
When Holt asked Clinton to address the email scandal, she offered a short and succinct answer: that she had made a mistake and would do things differently if she had the opportunity.
"That was more than a mistake," Trump shot back. "That was not a mistake. That was done purposefully."