If there is a skeleton key that commentators and political scientists have been using to make sense of recent events in American politics, it is political polarization: we now seem to see political polarization everywhere, from the halls of Congress and our state capitals to our choices about whom to vote for and even potentially about where to live or what to drink. But how should we understand today’s political polarization–are its stark divisions largely confined to party leaders and journalists, or are voters polarized, too? What are our best guesses about what caused today’s polarization, and what might increase or reduce it in the years to come? What are its likely consequences, both for domestic and foreign policy-making? And what about some of the most comparable developed democracies–have they experienced anything similar, or is polarization unique to America? Over the next few weeks, the Monkey Cage will be posting contributions from a wide variety of scholars and commentators speaking to those questions as we highlight what we do and don’t know about political polarization. Look for the inaugural post of the series tomorrow, when the Monkey Cage’s own Nolan McCarty will start things off by summarizing the key findings on polarization from a recent American Political Science Association report. Stay tuned…