Congressional Partisanship, Polarization Is Increasing, Report Says

Political polarization is on the rise, with the last two sessions of Congress an especially contentious group, according to a new analysis.

The Lugar Center, a think tank founded by former Indiana Republican Sen. Richard Lugar and Georgetown University's McCourt School of Public Policy, released its inaugural Bipartisan Index Tuesday, ranking members of Congress based on how frequently they work across the aisle.

The rankings are based on lawmakers’ sponsorship and co-sponsorship of bills, and measure the degree to which they succeeded in attracting co-sponsors from the opposing party and...