The United States, Russia, and Britain all have democratic political systems, but they have some key differences.

Similarities:

All three countries have a system of checks and balances in their government to prevent any one branch from becoming too powerful.They all have a bicameral legislative system, with two houses of parliament/congress.All three countries have regular elections to choose their political leaders.They all have a constitution that outlines the rights and responsibilities of their citizens.

Differences:

The United States has a presidential system, where the president is both the head of state and government. Russia has a semi-presidential system, with a president as head of state and a prime minister as head of government. Britain has a parliamentary system, where the prime minister is the head of government and the monarch is the head of state.The United States has a federal system, where power is divided between the national government and state governments. Russia has a centralized system of government, with most power held by the national government. Britain has a unitary system, where power is held by the central government.The United States has a two-party system dominated by the Republican and Democratic parties. Russia has a multi-party system, but is effectively dominated by the United Russia party. Britain also has a multi-party system, with the Conservative and Labour parties being the two main parties.The United States has a written constitution, which is considered the supreme law of the land. Russia has a constitution, but it is often ignored in practice. Britain does not have a single written constitution, but relies on a combination of written laws, conventions and traditions.