Article Photos: WHY IT MATTERS: Issues at stake in election 21/40

  FILE - In this Dec. 5, 2011 file photo, Occupy DC protesters watch morning commuters walk through McPherson Square in Washington. The income gap between the rich and everyone else is large and getting larger, while middle-class incomes stagnate. That's raised concerns that the nation's middle class isn't sharing in economic growth as it has in the past. And it sparked the Wall Street protests that spread to other cities in the country. (AP Photo/Evan Vucci, File)