The United States currently has two major political parties, the Republican and the Democratic. Other parties, called third parties, have formed in the country from time to time. Sometimes these parties are organized around a person, such as Teddy Roosevelt's Bull Moose Party in 1912. Sometimes third parties form around an issue, like segregation, as George Wallace's American Independent Party did in 1968 or the Prohibition Party which had a candidate for president on the ballot in every presidential election for 100 years.

Third parties, such as H. Ross Perot's United We Stand America, can make impressive showings. But third parties seldom receive many electoral votes. Perot received none in 1992. The few third-party candidates who have received electoral votes have never won. Even Teddy Roosevelt, who received more electoral votes in 1912 than the Republican nominee William Howard Taft, only succeeded in splitting the Republican vote and electing the Democrat, Woodrow Wilson.