Hyperpartisan

A political environment or behavior characterized by extreme, rigid adherence to party ideology, where compromise with the opposing party is viewed as a betrayal, and political strategy is focused entirely on defeating the opposition rather than governing.

Example: The repeated use of the ‘nuclear option’ in the Senate (changing the rules to allow nominations to pass by a simple majority, as in 2013 for most judicial and executive nominations) is often cited as a symptom of hyperpartisanship, eroding long-standing norms of bipartisan consensus.

Common misconception: Hyperpartisanship is a new phenomenon caused solely by social media. While social media amplifies it, political scientists trace the roots of modern hyperpartisanship to the ideological sorting of the parties that began in the 1970s and 1980s, accelerated by gerrymandering and changes in campaign finance.

Sources: https://www.congress.gov/ — Congressional Record, proceedings of Oct.-Nov. 2013 (the Senate rule change on nominations cited in the example); https://www.britannica.com/ — encyclopedia fallback: no official U.S. government source defines "hyperpartisan"; Britannica and political science literature cover polarization as a concept