The Lugar Center and McCourt School release latest bipartisan index rankings for Congress

The Lugar Center and the Georgetown University McCourt School of Public Policy today jointly released their new Bipartisan Index (BPI) rankings for 2023 — the first year of the current 118th Congress. The nonpartisan tool, which was launched in 2014, measures the degree to which Senators and Representatives work across party lines on legislation. Rep. Brian Fitzpatrick (R-PA) ranked first in the Bipartisan Index in the House of Representatives. Sen. Susan Collins (R-ME) reclaimed the top Senate spot after finishing second in the previous Congress. 

The Bipartisan Index quantifies how often members of Congress introduce bills that attract co-sponsors from the other party, and how often they in turn co-sponsor a bill introduced from across the aisle. The results showed an intensely partisan Congress, though one that was slightly improved from recent years.

“Bipartisan cooperation on legislation in 2023 was deficient by historical standards, though there were some marginal improvements in scores from the previous Congress,” said Lugar Center Policy Director Dan Diller. “It is especially disheartening that all eight new Senators who took office in January 2023 ranked in the bottom 30 percent of Senate scores.”

In 2023, 44 Senators scored above the historical average, while 54 scored below it. On the House side, 129 members topped the historical average, while 309 scored below it. Despite this negative outcome, 2023 represented a small improvement over the comparable first year of the previous Congress (2021). In that year, only 40 Senators and 109 House members scored better than the historical average of the BPI. 

In the House, Rep. Fitzpatrick continued his dominance of the Bipartisan Index. For the fifth consecutive year he led the House by a comfortable margin. He is the only House member who has ever been ranked first in the Bipartisan Index in multiple Congresses.

Sen. Collins, who led the Senate rankings for eight consecutive years between 2013 and 2020, before landing in second place in the 117th Congress, reclaimed the number one rank in 2023.  She was followed by three Democrats: Gary Peters (MI); Maggie Hassan (NH), who was the top ranked Senator in the previous Congress; and the retiring Joe Manchin (WV).

Katie Britt (R-AL), a first-year Senator who delivered the Republican response to President Biden’s State of the Union Address in February 2024, was the lowest scoring Senator. In the House, the lowest-scoring member was Jim Jordan (R-OH), who briefly emerged as a candidate for Speaker in October 2023, but failed to achieve the necessary support after several ballots.

The Bipartisan Index is based on a formula applied uniformly to all members that considers both the absolute numbers of bipartisan bills sponsored and co-sponsored and the percentage of such bills in a member’s portfolio. It excludes non-binding resolutions and ceremonial bills.  It also includes a metric that gives members credit for the number of bipartisan co-sponsors on their sponsored bills. The BPI uses a historical standard based on three decades of data to compare current members to historical averages. The Index outcome is determined entirely by the configuration of a member’s bill sponsorship and co-sponsorship portfolios. No subjective judgments are made about individual members or bills. 

Scores in the two chambers of Congress are based on separate data, so the scores of House members are not comparable to those of Senators.

Most Democratic Senators involved in closely-contested Senate races produced positive BPI rankings. Two Democratic Senators up for re-election — Jacky Rosen (D-NV) and Jon Tester (D-MT) ranked 6th and 10th respectively. Two other Democrats facing contested races — Tammy Baldwin (D-Wis) and Sherrod Brown (D-OH) came in lower, 31st and 39th respectively, but still above the historical average. 

In the House, both parties placed 15 members among the top 30 on the BPI. At the low end of the Index, Republicans had 17 members in the bottom 30, compared to 13 Democrats.

In the Senate, the largest split between Senators from the same state was Texas, where Republican John Cornyn ranked 5th for the second straight Congress, while his fellow Republican Ted Cruz, ranked 89th. The state with the highest-ranked pair of Senators was West Virginia, where Democrat Joe Manchin ranked 4th and Republican Shelley Capito ranked 13th. 

One of the bright spots of the 2023 Bipartisan Index was the very high scores of several first-year House members. Three new members ranked in the top five: Marc Molinaro (R-NY) was a strong 2nd to Brian Fitzpatrick; Mike Lawler (R-NY) was 4th; and Don Davis (D-NC) was 5th. Three other first-year House members — Zach Nunn (R-IA); Marie Gluesenkamp Perez (D-WA); and Jen Kiggans (R-VA) ranked among the top twenty House members.

The eight first-year Senators (six Republicans and two Democrats), however, weighed down the overall outcome of the Senate. Markwayne Mullin (R-OK) had the dubious honor of being the highest ranked new Senator at 72nd. Peter Welch (D-VT) was 75th; J.D. Vance (R-OH) was 77th; Ted Budd (R-NC) was 79th; Pete Ricketts (R-NE) was 85th; John Fetterman (D-PA) was 88th; Eric Schmitt (R-MO) was 97th; and Katie Britt (R-AL) was last at 98th. Laphonza Butler (D-CA), who replaced Sen. Dianne Feinstein after her death, was not scored because she served less than the requisite six months.

Although the top leaders of both houses are excluded from the BPI because their patterns of sponsorship and co-sponsorship are not comparable to the norms of other members, current Speaker of the House Mike Johnson (R-LA) is included in the results because he served more than six months of 2023 as a rank-and-file member. He ranked 423rd.

To see current and previous Bipartisan Index rankings, click here .