Special interest groups’ strategies of campaign contributions in the US are generally portrayed as service or policy-seeking. However, in line with the partisan theory of contributions, we argue SIGs decisions are strategic, involving competition and cooperation within industrial sectors. The argument feeds into the assumption of both Markov and social circuit conditional dependence of observations. Our hypothesis states SIGs strategic behavior is conditional on the neighboring network structure in which they are embedded. Using FEC contributions data (1980-2012), we apply an ERGM to estimate the effect of network structural forces on the probability a dyad of PACs contribute to the same candidates in the general election. The model gives two important results: (1) there is a great degree of homophily in PACs behavior within industrial sectors; (2) there is a significant tendency for local clustering configurations in the network, thus suggesting some degree of coordination of PACs campaign contributions.