Fredrik deBoer in the Washington Post:
That Clinton has unusually high unfavorables has been true for decades. Indeed, it has been a steady fact of her political life. She has annually ranked among the least-liked politicians on the national stage since she was the first lady. In recent years, her low favorability rating was matched only by that of her opponent, animated hate Muppet Donald Trump. In contrast, Sanders enjoys very high popularity, ranking as the most popular senator for two years in a row. Nationally, his favorability rating is more than 10 points higher than Clinton’s, and his unfavorability rating is more than 15 points lower. This popularity would have been a real asset on the campaign trail.
Clinton’s inability to ever capture the approval of most Americans hurt her in a number of ways. Consider her performance in predominantly black, working-class counties in Michigan. These are precisely the kinds of areas that she was supposed to count on in the Rust Belt, the “blue wall” that would supposedly secure her victory even if she lost out in Florida and North Carolina.
More here.