Political Parties in America
Why America has two parties, how they evolved, and what polarization means for governance.
The Two-Party System
The United States has had two dominant parties since the 1850s: the Democrats and the Republicans. This is largely a product of the 'first past the post' electoral system, where the candidate with the most votes wins — a structural feature that punishes third parties (known as Duverger's Law).
The parties have undergone dramatic transformations. In the mid-20th century, the Democratic Party shifted from a coalition that included Southern segregationists to the party of civil rights. Republicans, once the party of Lincoln and abolition, adopted the 'Southern Strategy' to appeal to white voters opposed to desegregation.
Today, Democrats generally favor a larger role for government, environmental regulation, and social liberalism. Republicans generally favor limited government, lower taxes, and social conservatism — though both parties contain significant internal diversity.