 Donnelly was the first Democrat to hold his seat since Vance Hartke's defeat by Richard Lugar in 1977.The Lugar Center, a Washington, D.C.-based nonprofit Lugar founded in 2013, ranked Donnelly the fourth most bipartisan Senator in the first session of the 115th United States Congress as well as the most bipartisan Democrat in the Senate.Donnelly was considered a moderate or conservative Democrat who "sometimes bucks his party on issues such as abortion, defense spending and the environment".