Democratic presidential candidate Elizabeth Warren may have apologized for taking a DNA test to prove she has Native American ancestry, but President Donald Trump could use his "Pocahontas" label for Warren to damage her as he did to defeat Hillary Clinton in the 2016 election, according to at least one Republican consultant. Warren can say she never used her ethnicity—her DNA test found she is between 1/64th and 1/1,024th Native American and backfired—to land a job. But Trump could use it against her to question her honesty. "If you give Trump a tool to equalize the playing field, which is...