For Americans of nearly every race, gender, political persuasion and location, disdain for Donald Trump runs deep, saddling the Republican front-runner with unprecedented unpopularity as he tries to overcome recent campaign setbacks. Seven in 10 people, including close to half of Republican voters, have an unfavorable view of Trump, according to a new Associated Press-GfK poll. It's an opinion shared by majorities of men and women; young and old; conservatives, moderates and liberals; and whites, Hispanics and blacks — a devastatingly broad indictment of the billionaire businessman. Even in the South, a region where Trump has won GOP primaries decisively,...