Politics in the United States has become more polarized in recent decades as both political elites and everyday citizens have been divided into rival and mutually antagonistic partisan camps. Increasingly, these rival camps question the political legitimacy and democratic commitments of the other side. Such polarization or “teamsmanship” can have a number of important political consequences: it can drive actors further apart, intensify political conflict, impede negotiation and compromise, and block the construction of bipartisan legislative and policymaking coalitions. Since polarization makes it difficult, if not impossible, to find common political ground, it can prevent democratic institutions from making important policy choices and responding to the critical issues of the day. Polarization, in short, can easily lead to democratic gridlock, paralysis, the decay of rights, and, in the extreme, violent conflict, as the Trump administration’s waning weeks so vividly demonstrated.