Each party is experiencing internal divisions as the Democrats have become more conservative than they were, in order to win back white worker and middle class support, and the Republicans are divided between the hard religious right and more moderate Republicans. Partisan Trends - Since the late 1960's there has been instability in the party system with a declining number of people registering as either Democrat or Republican. In time, the two major parties will reassert themselves again in th historical pattern we have had for well over 100 years. In my own view, the short-term factors thesis is more supported by evidence. This refers to smaller parties other than the Republicans or Democrats.
Third parties tend to be more parties of ideology and issues than the two major parties.
Some theorists argue that third parties erve a valuable function of suggesting ideas that are later adopted by one of the two major parties. For example, it is pointed out that a lot of the ideas of the New Deal were ideas supported by American socialists. Among the current third parties are the Reform Party or United We Stand America headed by Ross Perot. The Peace and Freedom Party, the Libertarian Party, the American Independent Party, the Democratic Socialists of America are current third parties. New York state has a Conservative Party.