WASHINGTON (AP) -- Donald Trump says he'll jail opponent Hillary Clinton if he wins the presidency.
The Republican presidential nominee made the threat — an unprecedented break with U.S. political decorum — in the middle of the second presidential debate, held Sunday in St. Louis.
It came as the Democratic nominee said it is "awfully good that someone with the temperament of Donald Trump is not in charge of the law in our country."
Trump blasted back, "Because you'd be in jail."
That drew applause in a town hall-style debate that was supposed to be free of audience participation.
A few moments earlier, Trump had said he'd instruct his attorney general to appoint a special prosecutor who would investigate the tens of thousands of emails that Clinton deleted when she was secretary of state.
After saying people across the country were "furious" with Clinton, Trump said, "So we're going to get a special prosecutor, and we're going to look into it." He added: "It's a disgrace. And honestly, you ought to be ashamed of yourself."
Trump's remarks drew widespread and bipartisan condemnation as un-American.
Former Attorney General Eric Holder, who served under President Barack Obama, wrote on Twitter: "In the USA we do not threaten to jail political opponents. @realDonaldTrump said he would. He is promising to abuse the power of the office."
Ari Fleischer, White House press secretary under George W. Bush and a supporter of Trump, wrote: "Winning candidates don't threaten to put opponents in jail. Presidents don't threaten prosecution of individuals. Trump is wrong on this."
Trump's "jail" line was one of the most-discussed debate moments on social media during the debate. Trump's campaign seemed proud of the moment, tweeting a video clip of the exchange shortly afterward with the message, "@HillaryClinton is NOT above the law!" Tens of thousands of his followers retweeted and "liked" the tweet, with some calling it a "mic-drop" moment and the best line of the debate.
The FBI and the Justice Department have closed their investigations into Clinton's use of a private email server when she was secretary of state.