To vote in a presidential election, you need to be an American citizen, be at least 18 years old on Election Day, and vote in the state in which you reside.<br /><br />Candidates tend to focus their campaigns on 'swing states,' where candidates from both parties have won in recent elections.<br /><br />The party with the most seats in each house gets the top leadership positions. That party has an enormous influence on which laws are considered and voted on.
