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. […] 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....