Analysis: How Partisan Is Today’s Senate?

By all accounts, the outcome of the 2020 election is historic.

President Trump became only the fourth elected incumbent in the last century to lose, while not one of the 166 Republicans seeking reelection to the House of Representatives lost.

Despite the enormous impact of Biden’s win, it is ushered in by fewer votes than Trump’s shocking win in 2016. If roughly 60,000 Americans in three states made different choices, Donald Trump would have earned 278 electoral votes and still be president. This holds true despite the highest turnout since 1900 and the popular vote margin expanding by about 5.5 million votes in Biden’s favor.

This election also saw the fewest state house switches since 1946, and for the first time since 1884, a Democrat president will take the oath of office without the benefit of a friendly Senate and is governing with the narrowest majority in the House for either party since 1919.

With that in mind, we did an analysis of Senate delegations to predict future trends and understand the true impact of polarization on both elections and governance at the federal level.

To view the interactive map and make your own analysis – click here.

Our analysis looked to discover if senate delegations had senators from the same party or different parties and how that changed over time. The results are fun to sift through and, in many ways, reflect changing regional partisan trends across America.

Here are some interesting facts:

  • Our current Senate is the most partisan senate since World War 2, with just six states having bipartisan delegations. The last time the country experienced this level of political uniformity was in the 1950s.
  • Since World War 2, the Senate has seen more Democratic leadership than Republican with 67% of the 42 Senates being Democrat. From 1939 to 1981, Republicans controlled the Senate only twice for a total of just four years in the majority.
  • The 116 and 117 senates are historically conservative. Their nearest comparators are the 109th Senate in 2005, during the second half of the Bush Administration, and the 84th Senate during the second half of Eisenhower’s first term.
  • Split ticket delegations peaked in the late 1970s and were common throughout most of the 1980s. GOP representation was most consolidated in the 1980s when their single delegation strength peaked.
  • Of the 33 seats up in 2022, 19 are Republican. Trump only won two states with split delegations and neither of them will be on the ballot in ’22.