In the United States, voter turnout—the percentage of qualified voters who vote—often depends on the type of election being held. More people tend to vote in presidential elections than in other kinds. This year is a "midterm" election; we are not voting for President.  

Some people ask the question, "Does my vote count?" because there are so many other voters.  In the 2000 presidential election, for example, only 51 percent of the electorate (all qualified voters) turned out.  Unfortunately, this was not considered unusual, BUT there were some voting issues during the 2000 election that drew lots of public attention.  Serious flaws in the voting process were revealed when the vote in Florida required a recount that lasted for 36 days. A close examination of the results showed that thousands of people had voted incorrectly, and thousands of other votes were unclear.
In fact, experts believe that between 1 and 4 percent of all votes are not counted as the voter intended. For over a month, Americans did not know who won the election.  It was kind of unsettling to say the least.

Some computer experts and citizens' groups continue to question the accuracy of computerized voting machines.

In 2004, a proposal to allow military personnel and other U.S. citizens living abroad to vote via the Internet was canceled after computer experts tested the process and found that it would be impossible to prevent hackers from tampering with election results.

Look at the graphs.  One show declining number of voters and the other shows the difference between turnout during Presidential and Midterm Elections.