Latest Vanderbilt Unity Index shows the U.S. continuing its trend toward increased political polarization

The Vanderbilt Project on Unity and American Democracy’s latest Vanderbilt Unity Index shows the country continuing its trend toward more polarization, ending 2023 down nearly three points from the start of the year. 

The VUI captures the amount of unity among Americans by collecting and analyzing data, including the public’s ideological commitment, polarization in Congress and presidential disapproval. Reflecting months of war between Israel and Hamas, multiple trials of former President Donald Trump and the kickoff of the 2024 presidential election season, the VUI from the fourth quarter of 2023 was 46.48 on a 100-point scale.  

This recent decline in the VUI was driven by two key components of the measure: Data shows that the number of Americans who identify as either extremely liberal or extremely conservative has increased, and the number of Americans who strongly disapprove of President Joe Biden increased. The last quarter of 2023 also showed us something unsurprising: The 118th Congress was even more polarized than before.   

This decline may continue into 2024 as battles for control of local, state and national governments continue.  

The 2023 Q4 VUI data shows:   

  • The percentage of Americans identifying as either strongly liberal or strongly conservative increased by 4 points, from 24 percent in the first quarter of 2023 to 28 percent in the last quarter of 2023.   
  • The percentage of Americans who strongly disapprove of the current president went up from 40 percent in the first quarter of 2023 to 44 percent in the last quarter of 2023.   
  • The Congressional polarization score for the 118th Congress stayed constant—88.55—throughout 2023; that was up one point from the fourth quarter of 2022.   

The overall level of unity has not dropped back to levels registered during Trump’s time in office: During the third quarter of 2020, the VUI was 40.16—the lowest score ever recorded. The highest-ever score was 72.33, recorded in 1991 as Soviet President Mikhail Gorbachev resigned and the Cold War ended. 

The VUI is composed of five inputs from publicly available survey data:  

  • Strong presidential disapproval  
  • Political and ideological extremism  
  • Social trust  
  • Political and social unrest  
  • Measurements of Congressional polarization  

Together, these diverse measures capture fluctuations in Americans’ general trust in their political institutions. It does not seek to measure the public’s reactions to particular policies. One of the five units measured by the index, political and social unrest, is typically updated every two years but could not be updated at the end of this quarter. In the future, the index will update the congressional polarization score each quarter instead of at the beginning of a new Congress to better capture the mood on Capitol Hill.   

More information on the Vanderbilt Unity Index is available online.