ABSTRACT: The literature on political parties suggests that strong partisan identities are associated with citizens’ effective interaction with the political system, and with higher levels of political trust. Traditionally, party identity therefore is seen as a mechanism that allows for political integration. Simultaneously, however, political parties have gained recent attention for their role in promoting societal polarization by reinforcing competing and even antagonistic group identities. This article uses General Social Survey data from 1972 – 2014 to investigate the relationship between partisan strength and both political and generalized trust. The findings show that increases in partisan strength are positively related to political trust, but negatively related to generalized trust. This suggests that while partisan strength is indeed an important linkage mechanism for the political system, it is also associated with a tendency toward social polarization, and this corrosive effect thus far has not gained sufficient attention in literature on party identity.