Some elections are defined by the gap between the rich and the poor. Others are defined by the gap between the left and the right. But this election will be shaped by the gap within individual voters themselves  the gap between their private optimism and their public gloom.

American voters are generally happy with their own lives. Eighty-six percent of Americans say they are content with their jobs, according to the General Social Survey. Seventy-six percent of Americans say they are satisfied with their family income, according to a Pew Research Center survey. Sixty-two percent of Americans expect their personal situation to get better over the next five years, according to a Harris Poll, compared with only 7 percent who expect it to get worse.

Researchers from Pew found that 65 percent of Americans are satisfied over all with their own lives  one of the highest rates of personal satisfaction in the world today.

On the other hand, Americans are overwhelmingly pessimistic about their public institutions. That same Pew survey found that only 25 percent of Americans are satisfied with the state of their nation. That 40-point gap between private and public happiness is the fourth-largest gap in the world  behind only Israel, Mexico and Brazil.