Eliminate The Republican Party

America's two-party system is based on laws, party rules and custom, not specifically outlined in the US Constitution. Several third parties also operate in the U.S., and from time to time elect someone to local office. The modern two-party system consists of the "Democratic" Party and the "Republican" Party.

The US has a two-party political system because of two structural features in American politics: single-member districts and winner-take-all elections. Both features encourage the existence of 2 major parties, as smaller parties face great difficulty in winning elective office.

There can be no doubt that the Electoral College has encouraged and helps to maintain a two- party system in the United States. This is true simply because it is extremely difficult for a new or minor party to win enough popular votes in enough States to have a chance of winning the presidency.

The Second Party System increased American political engagement by democratizing politics when previously elected officials were chosen primarily by the wealthy elite.  Supporters of the system's two dominant parties were divided along philosophical and socio-economic lines.

What would happen in the USA if the Republican Party was destroyed or eliminated by voting and only the Democratic Party remained to decide how the government was operated?

We cannot consider one party system as a good option because this is not a democratic option. Any democratic system must allow at least two parties to compete in elections and provide a fair chance for the competing parties to come to power. Moreover people do not get any choice in this system.

China and North Korea have a one party government...  even Russia does not have a one party government...