Partisanship refers to the strong identification and support for a particular political party or ideology. It influences individuals' political beliefs, attitudes, behaviors, and voting patterns. Partisanship can lead to polarization and division among different political groups, as individuals may be more inclined to support their own party's policies and candidates, while rejecting those of opposing parties. Researchers study partisanship to better understand its effects on political decision-making, public opinion, and the overall functioning of democratic societies.