A new Battleground Poll shows that “voters tend to describe themselves as angry, pessimistic, anxious, and depressed,” says Celinda Lake, president of Lake Research Partners, a political strategy firm that works for Democratic candidates. Ms. Lake and Republican pollster Ed Goeas jointly oversee the Battleground Poll. Things may get worse for office holders after Christmas, as voters deal with holiday bills and with the effects of layoffs that often come just before the end of the year. “Whatever mood the voters are in right now, they are likely to be in a particularly ornery mood toward every elected official by...