Most of the U.S. Census data about voting and registration from the
November 2012 general election focus on voters, but it also examines why
nonvoters did not vote. According to analysis by the Pew Charitable Trusts, the two (of 11 possible) most common reasons
were:

1. Election administration problems were a factor as well. Nationwide, 5.5
   percent of nonvoters—estimated at more than 1 million—said they did not vote
   due to registration problems, more than those who said they did not
   vote because of bad weather, forgetting, or transportation problems.
   Additionally, nonvoters who lived at their residence for less than a
   year were more likely to have cited registration problems than those who
   had lived at their residence for three years or more—11.7 percent and 3
   percent, respectively.
2. voters being too busy or not being interested in the election.

However, our research says that these voter responses actually mean:

What they say  -->  What they mean

• Don’t like the choices --> Don't know the candidates/issues
• My vote won’t count --> Don't feel own opinion matters
• Takes too much time --> Don't know how to vote
• It’s inconvenient
  -->  Intimidated by the process

More about our research: http://cavotes.org/research.