These topics are explained in detail in earlier sections, so use this section as a reminder and review.

Political Polarization

The US became more politically polarized, especially after the 1990s. The Reagan Revolution moved much of the country to the conservative right, but many in the 21st century began to push back against conservatives and/or continued to fight for the liberal legacy of programs like the New Deal and Great Society. 

Political polarization in the United States has been a significant trend in the 21st century, with many Americans feeling increasingly divided along political lines. There are a number of factors that have contributed to this polarization, including:

1. The role of social media and the internet: The rise of social media and the internet has made it easier for people to access and share information, but it has also made it easier for people to encounter and engage with political content that confirms their preexisting beliefs. This can lead to a phenomenon known as "echo chambers," in which people are exposed to only one side of an issue, leading to increased polarization.
2. The role of political parties: Political parties in the United States have become increasingly polarized in recent years, with the Democratic Party and the Republican Party taking more extreme positions on a range of issues. This has made it more difficult for politicians to work together and find common ground, leading to increased polarization.
3. The role of media: The media landscape in the United States has become increasingly fractured, with people able to access news and information from a wide range of sources. This has made it easier for people to access information that confirms their preexisting beliefs, leading to increased polarization.
4. The role of campaign finance: The role of money in American politics has long been a controversial issue, and many people believe that the influence of campaign finance has contributed to political polarization. The ability of wealthy individuals and special interest groups to fund political campaigns has led to a system in which politicians are more beholden to their donors than to the general public, leading to increased polarization.
5. Demographic changes: The United States is undergoing significant demographic changes, with a more diverse and urban population. These changes have led to increased political polarization, as different groups have different political interests and priorities. Overall, there are a number of factors that have contributed to the political polarization in the United States in the 21st century, including the role of social media, the role of political parties, the role of media, the role of campaign finance, and demographic changes.

Economic Changes

Globalization affected the United States greatly during this time period as the US economy moved to a post-industrial basis, focusing more on service-sector and high-tech jobs. This created problems for previous industrial centers (see the Rust Belt) and worsened the country’s economic inequality as the rich got richer and poor and middle class wages stagnated. 

There have been a number of significant economic changes in the United States in the 21st century, and a number of different factors have contributed to these changes. Here are five causes of economic changes in the United States in the 21st century:

1. The Great Recession: The Great Recession was a major economic downturn that lasted from 2007 to 2009, and it had a significant impact on the economy of the United States. The recession was caused by a number of factors, including the collapse of the housing market and the financial crisis. The recession led to high levels of unemployment and a slowdown in economic growth.
2. The COVID-19 pandemic: The COVID-19 pandemic has had a significant impact on the economy of the United States, with many businesses shutting down and millions of Americans losing their jobs. The pandemic has led to a slowdown in economic growth and increased levels of unemployment.
3. Changes in tax policy: The United States has undergone a number of changes in tax policy in the 21st century, including the implementation of the Tax Cuts and Jobs Act in 2017. These changes have had a significant impact on the economy, with some people arguing that they have helped to stimulate economic growth, while others argue that they have led to increased income inequality.
4. Changes in trade policy: The United States has undergone a number of changes in trade policy in the 21st century, including the withdrawal from the Trans-Pacific Partnership (TPP) and the renegotiation of trade agreements with countries like Mexico and Canada. These changes have had a significant impact on the economy, with some people arguing that they have helped to protect American jobs, while others argue that they have led to increased prices and reduced access to global markets.
5. Changes in monetary policy: The Federal Reserve, the central bank of the United States, has implemented a number of changes in monetary policy in the 21st century, including the implementation of low interest rates and the implementation of quantitative easing programs. These changes have had a significant impact on the economy, with some people arguing that they have helped to stimulate economic growth, while others argue that they have led to increased levels of inflation. Overall, there are a number of factors that have contributed to the economic changes in the United States in the 21st century, including the Great Recession, the COVID-19 pandemic, changes in tax policy, changes in trade policy, and changes in monetary policy.

Demographic Changes

The US in the 21st century was much more diverse than the US of 1950 or even of 1980. Continued immigration from Latin America and Asia created tension within the US as the US—again—wondered about how to assimilate immigrant groups and to maintain a US identity. Women were more involved in the workforce than ever before, movement to the Sunbelt continued as Midwestern states lost population relative to the rest of the country. 

There have been a number of significant demographic changes in the United States in the 21st century, and a number of different factors have contributed to these changes. Here are five causes of demographic changes in the United States in the 21st century:

1. Immigration: The United States has a long history of immigration, and the 21st century has seen a significant influx of immigrants from Latin America and Asia. This has led to a more diverse population and has contributed to the growth of the Hispanic and Asian American populations.
2. Changes in birth rates: The 21st century has seen significant changes in birth rates in the United States, with the fertility rate falling to its lowest level in more than three decades. This has contributed to the aging of the population and has led to a shift in the age structure of the population.
3. Changes in family structure: The 21st century has seen significant changes in family structure in the United States, with an increase in single-parent households and a decline in the number of married couples with children. This has contributed to changes in the demographics of the population.
4. Changes in life expectancy: The 21st century has seen significant changes in life expectancy in the United States, with life expectancy increasing due to improvements in healthcare and technology. This has contributed to the aging of the population and has led to a shift in the age structure of the population.
5. Changes in geographic mobility: The 21st century has seen significant changes in geographic mobility in the United States, with more people moving between states and regions. This has contributed to changes in the demographics of the population and has led to a more diverse and urbanized population. Overall, there are a number of factors that have contributed to the demographic changes in the United States in the 21st century, including immigration, changes in birth rates, changes in family structure, changes in life expectancy, and changes in geographic mobility.