With public frustration at both political parties running high, the calls for third-party candidates have begun. Here's a look at notable third-party candidates for president, from Cynthia McKinney in 2008 to Strom Thurmond in 1948.
Texas businessman Ross Perot, who espoused right-leaning ideas, ran for president twice as a third-party candidate: In 1992 as an independent and in 1996 as a Reform Party candidate.(AP Photo/Ben Margot)
George Wallace, the four-time governor of Alabama and symbol of resistance to civil rights, ran for president on the American Independent Party ticket in 1968.(AP photo)
Seen here when he was South Carolina's governor, Strom Thurmond raises his hands over his head in response to a tumultuous ovation from delegates to the Dixiecrat's State's Rights Convention in Birmingham, Ala., on July 17, 1948. The convention nominated Thurmond for president.(AP Photo)
Ralph Nader has run for president four times, in 1996, 2000, 2004, and 2008, on various party tickets: Reform, Green, as well as an independent.(AP Photo/George Ruhe)
Noted commentator Pat Buchanan ran for president on the Reform Party ticket in 2000.(AP Photo/Stephan Savoia)
The Libertarian Party nominated former Rep. Bob Barr, R-Ga., as its candidate in 2008.(AP Photo/Ed Andrieski)
Former U.S. Rep. Cynthia McKinney, D-Ga., was the Green Party's nominee in 2008.(AP Photo/Ric Feld)