Robert Oldham’s research while affiliated with Princeton University and other places

It is often argued that bipartisan lawmaking depends on minority legislative parties controlling institutional veto points through divided government and/or supermajority pivots. Using a new dataset of state legislative rollcall votes on tax increases—an issue where states vary in whether they require majority or supermajority votes—I assess (1) whether minority control of veto points is necessary for bipartisan policymaking and (2) whether there are greater levels of partisan governance when the majority controls all veto points. I find that partisan governance is more likely when the majority controls all vetoes. However, bipartisan policymaking is still the most common outcome even when institutional conditions are seemingly ideal for partisan governance. Interviews with state policymakers uncover various noninstitutional reasons for bipartisanship regardless of veto control. My findings suggest that while institutional rules can compel bipartisanship, they are just one of many reasons why the minority party participates in lawmaking.