The Republican Party was one of the original parties in Janda's 1950-1962 ICPP study. The party continued throughout 1950-1990 in the Harmel-Janda study of party change.

The essay on party politics in the United States from 1950 to 1962 says:

Nearly always the minority party in Congress, the Republicans fared much better in presidential elections, winning four of the seven and holding the presidency for 16 of the 29 years from 1950 to 1978 (Eisenhower in 1953-1960 and Nixon in 1969-1976).

The essay on party politics in the United States from 1963 to 2000 says:

Since 1962, the Republicans won the presidency five times: 1968 and 1972 (Nixon), 1980 and 1984 (Reagan), and 1988 (Bush). The 1994 election has been dubbed the "Republican Revolution," for the party took control of the House for the first time since 1954 and also wrested back control of the Senate. The party kept control of both chambers through the rest of the century.

Consult the index to variables for annual scores of the party's issue orientation, organizational complexity, centralization of power, and coherence from 1950 through 1990.