  Previous research indicates that race, ethnicity, and gender influence
legislative behavior in important ways. The bulk of this research, however,
focuses on the way these characteristics shape an individual legislator's
behavior, making it less clear how they account for relationships between
legislators. We study the cosponsorship process in order to understand the race
and gender based dynamics underlying the relational component of
representation. Using a temporal exponential random graph model, we examine the
U.S. House cosponsorship network from 1981 through 2004. We find that Black and
Latino members of Congress are at a comparative disadvantage as a result of
race-based assortative mixing in the cosponsorship process, yet this
disadvantage is mitigated by the electoral pressures that all members face.
Members representing districts with significant racial and ethnic minority
populations are more likely to support their minority colleagues. We also find
that women members do not appear to face a similar disadvantage as a result of
their minority status. We argue that these race and gender dynamics in the
cosponsorship network are the result of both the inherent tendency towards
intra-group homophily in social networks and the electoral connection, which is
manifested here as members supporting minority colleagues to broaden their own
electoral base of support among minority constituencies.
