WATCH: Why for some voters the latest campaign ad doesn't matter.
Political ads are still up on the TV, and the candidates are still exchanging barbs, but for some voters none of this matters anymore.
They have already cast their vote-- either by using early voting or absentee voting.
In 2012, more than 30 percent of voters cast their ballots before election day-- the highest percentage ever, and it's expected to grow this year.
Rules governing voting before election day
The rules vary from state to state, but generally speaking, absentee voting is done via the mail whereas early voting is done in person before election day. Some states require you to have an excuse in order to vote absentee.
Currently, 34 states plus D.C. allow for early voting, 3 states conduct their election completely by mail, and 13 states don't have early voting and require an excuse in order to vote absentee.
So how did we get to the point where voters are casting their ballots before election day?
Absentee voting was created during the Civil War as a way to allow the troops who were away from home to vote.
Widespread usage is new
In 1978, California implemented no excuse absentee voting. Today every state west of the Mississippi River except for Missouri allows for early voting.
Voters from both parties vote early
The results from ballots returned before election day are not reported until the polls close on election day. So there's no way to know who is ahead or behind in the early vote.
Predictions are made, but they are based on the party registration of the early voters, without knowing who they actually voted for.
So vote early, vote on time, but just don't vote late and don't vote twice.