Answer:
People were particularly motivated by one of the candidates
Explanation:
The voter turnout in 2008 spiked because people were particularly motivated by Barrack Obama. His running for presidential position represented a "generational change." So, this means that many of the voters, especially the African-Americans ages 18 to 25 years old became interested in registering in order to vote.
Such kind of voter turnout spike is said to have also occurred during the candidacy of John F. Kennedy, where the voter turnout was 62.8 percent. This was because Kennedy was a charismatic leader who also represented a generational change.
So, this explains the answer.