Crossing Over: Majority Party Control Affects Legislator Behavior and the Agenda

Nicholas G Napolio,Christian R Grose

doi:10.1017/s0003055421000721

Abstract

Does majority party control cause changes in legislative policy making? We argue that majority party floor control affects legislator behavior and agenda control. Leveraging a natural experiment where nearly one tenth of a legislature’s members died within the same legislative session, we are able to identify the effect of majority party floor control on the legislative agenda and on legislator choices. Previous correlational work has found mixed evidence of party effects, especially in the mid-twentieth century. In contrast, we find that majority party control leads to (1) changes in the agenda and (2) changes in legislators’ revealed preferences. These effects are driven by changes in numerical party majorities on the legislative floor. The effects are strongest with Republican and nonsouthern Democratic legislators. The effects are also more pronounced on the first (economic) than the second (racial) dimension. Additional correlational evidence across 74 years adds external validity to our exogenous evidence.

Highlights

The majority party’s agenda setting in the US Senate, with its emphasis on individual power
Leveraging a natural experiment where nearly one tenth of the chamber’s senators died within the same legislative session, we identify the exogenous effect of party control on agenda control and legislator behavior
This research shows that majority party control affects legislative behavior and agenda setting, and the magnitude of the effect is larger than has been uncovered in past correlational studies

Summary

Data and Empirical Tests

We collected all roll-call votes from the 83rd Senate and separated them into regimes (see Appendix A for details on each regime, defined as each unchanging composition of senators). If the status quo policy was on the left of the spectrum, say at –0.5, and the policy proposal was on the right of the spectrum, say at 0.5, it would divide senators by ideology down the middle of the first dimension at 0, the bill’s cutpoint. A senator with ideal point 0 would be indifferent between the status quo and the new proposal. We would observe senators voting nay who were to the left of the cutpoint, with negative ideal points, preferring the status quo, but senators on the right of the cutpoint, with positive ideal points, voting for the bill. According to the party-agenda-control model, cutpoints should cluster around moderate to low values (liberal policies), as these are the status quo policies the majority party would like to revise that could garner a sufficient majority to move policy toward the party median. When the majority in the Senate switches to Democratic control, the

Party Control

Democratic Majority Observations

Standardized First Dimension Ideal Point

Democratic Majority Observations Senator FEs

Findings

CONCLUSION