The Lugar Center and Georgetown University’s McCourt School Unveil 2015 Bipartisan Index Rankings for All Members of Congress

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Sen. Collins and Rep. King Top Index; Progress Has Been Made

March 7, 2016

Media Contacts:

Lauren Mullins

Betsy Holahan

WASHINGTON, D.C. — The Lugar Center, led by former U.S. Senator Richard Lugar, and the McCourt School of Public Policy today jointly released their new Bipartisan Index rankings of all members of Congress in 2015.  The non-partisan tool indicates the degree to which Senators and Representatives work across party lines.

“This new data indicates that though Congress continues to be a highly partisan institution, some progress is being made,” said Lugar Center President Richard G. Lugar, who served for 36 years as a Republican Senator from Indiana. “Lawmakers with strong ideological views can still find common ground with members across the aisle if they make an effort to do so.  Some members of Congress have embraced this challenge, despite the intensely partisan political culture exemplified in the national presidential campaigns."

The rankings of the 114th Congress, based on bill sponsorship and co-sponsorship, follow the initial Bipartisan Index data for the 113th Congress (2013-14), which was one of the most partisan of the past 20 years, and provides historical context for the increased partisanship in Congress over the past two decades.

“Many believe the political process in Washington to be broken beyond repair,” said Edward Montgomery, dean of the McCourt School. “We hope the Bipartisan Index reminds lawmakers and their constituents that effective governance requires leadership - and in today’s strident partisan environment, that means working across the aisle to find solutions to our most pressing problems.”

The new data allows voters to see over time how willing their Senators and Representatives have been to work across party lines.  Based on the scores, Senator Susan Collins (R-ME) was the most bipartisan senator and Representative Peter King (R-NY) was the most bipartisan representative, followed very closely by Representative Christopher Gibson (R-NY).

The Bipartisan Index measures how often a member of Congress introduces bills that succeed in attracting co-sponsors from members of the other party, and how often they in turn co-sponsor a bill introduced from across the aisle.  The Index is based on a formula applied uniformly to all members. No subjective judgments are made about individual members or bills. The Index serves as a critical resource for voters and the media and, its sponsors hope, encourages lawmakers to be more bipartisan when writing or co-sponsoring legislation.

In the Senate, 38 lawmakers got a positive score for 2015, compared with 36 for the entire 113th Congress (2013-2014). In the House, 137 Members were above zero in 2015, down from 142 in 2013-2014.  But Bipartisan Index scores tend to rise modestly during the second year of a Congress due to Index components that benefit from the accumulation of bipartisan bills and co-sponsorships.  Therefore, it is likely that scores for the entire 114th Congress will beat those of the 113th, though they will still be below the 20-year norm.

The Bipartisan Index rankings for the 113th Congress, released in May 2015, covered both the House and the Senate. Rankings released in December 2015 covered all Senators who served in the 11 Congresses between 1993 and 2014.  Rankings for the House of Representatives who served in the 11 Congresses between 1993 and 2014 will be released later in 2016. To see current and previous rankings, visit



About The Lugar Center:

Under the leadership of former U.S. Senator Richard Lugar, the non-profit Lugar Center is a platform for informed debate and analysis of global issues, including nonproliferation of weapons of mass destruction, global food security, foreign assistance effectiveness and global development, energy security, and enhancing bipartisan governance.

About the McCourt School of Public Policy:

Founded in 1996 as the Georgetown Public Policy Institute, the McCourt School of Public Policy at Georgetown University is a top-ranked graduate school located at the center of the policy world in Washington, D.C. Our mission is to give our students the rigorous quantitative and analytic skills needed to design, implement and evaluate smart policies and to conduct policy research and recommend effective solutions on today’s most critical topics.