When dened in terms of social identity and aect toward co-partisans and op-posing partisans , the polarization of the American electorate has dramatically increased .
We document the scope and consequences of aective polarization of partisans using implicit , explicit and behavioral indicators .
Our evidence demon strates that hostile feelings for the opposing party are ingrained or automatic in voters' minds , and that aective polarization based on party is just as strong as polarization based on race .
We further show that party cues exert powerful eects on non-political judgments and behaviors . Partisans discriminate against opposing partisans , and do so to a degree that exceeds discrimination based on race .
We note that the willingness of partisans to display open animus for oppos-ing partisans can be attributed to the absence of norms governing the expression of negative sentiment and that increased partisan aect provides an incentive for elites to engage in confrontation rather than cooperation .