May 14, 2024 - Politics & Policy

The most bipartisan members of the U.S. Senate

A bar chart shows the most bipartisan senators of 2023 according to The Lugar Center's Bipartisan Index scores, based on sponsored and co-sponsored bills. Senator Susan Collins, a Republican from Maine, leads the list with a score of 2.4. Democratic Senator Gary Peters of Michigan follows with a score of 2.2. There are five republicans and five democrats in the top 10.
Data: The Lugar Center; Chart: Sara Wise/Axios

Sen. Susan Collins (R-Maine) is the most bipartisan senator, according to the the Lugar Center's index for 2023, which takes into account bills sponsored or co-sponsored by members of both parties.

Why it matters: Collins, whose state has voted for the Democratic presidential candidate in the last eight elections, has been known to break with her party including on abortion and in refusing to endorse former President Trump.

  • The 10 most bipartisan senators were evenly split between the two parties.

Zoom in: Sen. Gary Peters (D-Mich.) came in second for bipartisanship — reflective of the battleground state he represents.

  • Sen. John Cornyn (R-Tex.) is the only Republican vying for Senate leadership to make the list.
  • Sen. Lisa Murkowski (R-Alask.) is one of just three GOP senators to not endorse Trump.
  • Sens. Jon Tester (D-Mont.) and Jacky Rosen (D-Nev.) are both facing serious GOP challengers this year.
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