Briefly describe the overall pattern in the way the two major parties have competed for and held power in american history

The influence of Both Democrate and Republican party acted like a pendulum that constantly change the dominant political view of American history.

The Republican party was always known as the party that advocated less-government involvement, lower tax-rate, and strong miltary, while the democratic party was always known as the party that advocated more-government involvement, higher tax-rate, higher censorship, and higher government spending for welfares.