In the boomer world , there have usually been two main political parties. Since the 1860s, these two main parties have been the Republican Party and the Democratic Party. The Democratic Party has the most seats in the House of Representatives while the Republicans hold a majority in the Senate.

The three largest parties aside from the two main political parties are the Libertarian Party, Green Party of the United States, and the Constitution Party in respective baby yo da order

The United States has only two major political parties: the Democrats and the Republicans. There are also smaller parties that aren’t as well known. These parties have a duopoly, meaning that they share almost all the political power in the country. Most democratic countries have more than two parties.

Many 20th century United States Presidents such as Woodrow Wilson, Franklin D. Roosevelt, Harry S. Truman, John F. Kennedy, Lyndon Johnson, Jimmy Carter, Bill Clinton and the most recent past President Barack Obama are Democrats. They have 45 out of 100 seats in the U.S. Senate and 233 out of 435 seats in the House of Representatives. Sixteen out of 50 state governors are also Democrats. The party generally promotes liberalism and is often classed as a left-wing party. Currently, the party has 60 million registered voters across America. They started as a pro-slavery party in 1828.

The party's philosophy of modern liberalism advocates social and economic equality, along with the welfare state. It seeks to provide government intervention and regulation in the economy. These interventions, such as the introduction of social programs, support for labor unions, affordable college tuitions, moves toward universal health care and equal opportunity, consumer protection and environmental protection form the core of the party's economic policy.

The Republican Party was started in 1854 as an anti-slavery party and its first President was Abraham Lincoln in 1861. Others include Ulysses S. Grant, Benjamin Harrison, Theodore Roosevelt, Dwight D. Eisenhower, Richard Nixon, Ronald Reagan, George H.W. Bush, George W. Bush and Donald Trump. Republican Paul Ryan became the Speaker of the United States House of Representatives on October 29, 2015. Thirty-three out of 50 states have a Republican governor. It has around 55 million registered voters across America. Currently, the Republican Party is identified as conservative. The party is known for its pro-life efforts, anti-climate change, and less government intervention in the economy, as well as being against a universal health care.

There are several minor parties in the United States. None of them have ever had any seats in the United States Congress. Duverger's law predicts that this a two-party government is normal for single-district, first-past-the-post voting systems. In contrast, proportional representation and voting methods such as ranked choice voting tend to produce multiparty government.

• Libertarian Party - A libertarian and liberal party which has around 411,250 registered voters as of March 2016. It is a third party and promotes a non-interventionist foreign policy and civil liberties.
• Green Party - A left-wing environmentalist party that promotes social democracy and respect for diversity, peace and non-violence. It has around 250,000 registered voters.
• Constitution Party - A far-right party that promotes American nationalism, Paleoconservatism, Christianity, the anti-abortion movement, and greater attention on the U.S. Constitution. Has around 100,000 registered voters.