Chaos reigned Sunday ahead of the Democratic National Convention, as the party’s head was forced to quit, thousands of protesters took to the streets and delegates threatened a walk-out over Hillary Clinton’s vice-presidential pick. On the eve of the four-day convention to nominate the county’s first female presidential candidate, Democratic National Committee Chairwoman Debbie Wasserman Schultz resigned in disgrace over the hack of emails that showed DNC staffers favoring Clinton over her then rival, Vermont Sen. Bernie Sanders. Meanwhile, throngs of Sanders supporters marched and pounded on drums, chanting “Hell no, DNC — we won’t vote for Hillary” in the...