There are numerous reasons why the American political system has settled in to a binary system of major parties -- some of them purely mathematical. Nevertheless, nothing prevents a third party candidate from trying a run for President -- and third parties have found the occasional success at the state and local levels.
To date, no third party has successfully landed a spot in the White House -- but not for lack of trying. Here's a list of the most notable third party candidacies in American history:
| Candidate | Year | Party | % of Popular Vote | Key Positions/Platform |
|----------------------|------|-------------------------------|-------------------|------------------------------------------|
| John C. Frémont | 1856 | Republican (pre-major party) | 33.1% | Anti-[[slavery]], Western expansion |
| John Bell | 1860 | Constitutional Union | 12.6% | Maintaining the Union, avoiding sectional conflict |
| [[Horace Greeley]] | 1872 | Liberal Republican | 43.8% | Civil service reform, reconciliation between North and South |
| James B. Weaver | 1892 | Populist | 8.5% | Government control of railroads, monetary reform, pro-farmer policies |
| Eugene V. Debs | 1912 | Socialist | 6.0% | Social ownership of industry, workers' rights, labor reforms |
| Robert M. La Follette | 1924 | Progressive | 16.6% | Anti-trust, workers' rights, pro-farmer policies |
| Strom Thurmond | 1948 | Dixiecrat (States' Rights) | 2.4% | States' rights, racial [[segregation]] |
| [[George Wallace]] | 1968 | American Independent | 13.5% | States' rights, law and order, segregationist policies |
| John B. Anderson | 1980 | Independent | 6.6% | Fiscal responsibility, balanced budget, social progressivism |
| Ross Perot | 1992 | Independent | 18.9% | Fiscal responsibility, balanced budget, opposition to NAFTA |
| Ralph Nader | 2000 | Green | 2.7% | Environmentalism, campaign finance reform, consumer protection |