Jeffrey M. Stonecash is Maxwell Professor in the Maxwell School, Syracuse University. He does research on political parties, changes in their electoral bases, and how these changes affect political polarization and public policy debates. His recent books are Class and Party in American Politics (2000), Diverging Parties (2002), Political Polling (2003), Parties Matter (2005), Split: Class and Cultural Divisions in American Politics (2007), Reassessing the Incumbency Effect (2008), Dynamics of American Political Parties (2009), Understanding American Political Parties (2012) and Party Pursuits