Why does a large and united membership strengthen an interest group?

A large and united membership strengthens an interest group by increasing its political leverage and influence over government officials.1

When a group possesses a large, geographically dispersed membership, it often impacts employment and economic interests across many legislative districts. This makes legislators more likely to be receptive to the group's concerns, as they are accountable to those constituents. Furthermore, a cohesive and large membership demonstrates the group's ability to mobilize, which is a critical factor in determining its political clout.1

While some theories suggest that smaller groups are easier to organize, the impact of size is often mediated by the group's internal dynamics. A united group that maintains high levels of interaction and networking among its members can more effectively overcome collective action problems, such as the temptation for individuals to "free ride". Ultimately, the combination of size and cohesiveness allows a group to present a more formidable presence, making it a more significant force for policy makers to consider when crafting legislation.21