The Calculus of Cosponsorship in the U.S. Senate

Abstract

We investigated why a legislator would be willing to vote “yea” on final passage of a bill but would choose not to cosponsor that bill. We tested a series of hypotheses regarding the cosponsorship decisions of individual senators, using a dataset that includes every major initiative that was introduced and received a floor vote in the Senate between 1975 and 2000. We found that senators are more likely to cosponsor bills when their preferences diverge from the Senate median but are closer to those of the bill's sponsor. Also, senators are more likely to cosponsor bills when they sponsor a higher number of bills overall, when they become more connected with colleagues, and when their constituents increase demand for legislation within particular policy areas. Senators are less likely to cosponsor bills if they received a higher percentage of the general election vote in their most recent election.

Geography and power in an organizational forum: Evidence from the U.S. Senate Chamber

“…In examining the paucity of co‐sponsorship patterns, Campbell () suggests that “co‐sponsorships, if offered too freely, lose some of their impact and value.” Moreover, co‐sponsorship is often a strategic component of legislative action, serving as either a signal to their fellow legislators (Kessler and Krehbiel, ) or as a means to gain influence. Indeed, Fenno's () case study of the Republican Senator Dan Quayle's Job Training Bill suggests “the decision to travel the bipartisan route and to solicit the help [and co‐sponsorship] of Edward Kennedy was his [Quayle's] earliest strategic decision.” As expected, co‐sponsorship is more likely to occur when individuals share similar ideologies (Harward and Moffett, ).…”

“…Indeed, Fenno's (1989) case study of the Republican Senator Dan Quayle's Job Training Bill suggests "the decision to travel the bipartisan route and to solicit the help [and co-sponsorship] of Edward Kennedy was his [Quayle's] earliest strategic decision." As expected, co-sponsorship is more likely to occur when individuals share similar ideologies (Harward and Moffett, 2010).…”

Stamps of Power and Conflict: Imprinting and Influence in the U.S. Senate, 1973-2005

“…In particular, the ideological distance between senators is negatively related to their tendency to cosponsor one another's bills (Chown and Liu 2015;Harward and Moffett 2010). In other words, it is harder for a focal senator to enlist a colleague as a cosponsor when that colleague's political ideology differs significantly from his or her own.…”

Expertise, Networks, and Interpersonal Influence in Congress

“…High levels of cosponsoring make prospective cues both more useful and more credible. First, cosponsoring indicates approval of the sponsor's bill, and implies that the sponsor and cosponsor share some common ground as to what constitutes good legislation (Kessler and Krehbiel, 1996;Harward and Moffett, 2010). This increases the likelihood that the sponsor will identify features of legislation that are important to the cosponsor and also makes the sponsor's vote on any given piece of legislation a more useful proxy for how the cosponsor would vote were she fully informed.…”