Although interest groups are probably better known for their attempts to influence legislative and executive branch decisions, they also pursue their policy goals in the courts. Some groups have found the judicial branch to be more receptive to their efforts than either of the other two branches of government. Interest groups that do not have the economic resources to mount an intensive lobbying effort in Congress or a state legislature may find it much easier to hire a lawyer and find some constitutional or statutory provision upon which to base a court case. Likewise, a small group with few registered voters among its members may lack the political clout to exert much influence on legislators and executive branch officials. Large memberships and political clout are not prerequisites for filing suits in the courts, however.

Interest groups may also turn to the courts because they find the judicial branch more sympathetic to their policy goals than the other two branches. Throughout the 1960s interest groups with liberal policy goals fared especially well in the federal courts. In addition, the public interest law firm concept gained prominence during this period. The public interest law firms pursue cases that serve the public interest in general -- including cases in the areas of consumer rights, employment discrimination, occupational safety, civil liberties, and environmental concerns.

In the 1970s and 1980s conservative interest groups turned to the federal courts more frequently than they had before. This was in part a reaction to the successes of liberal interest groups. It was also due to the increasingly favorable forum that the federal courts provided for conservative viewpoints.

Interest group involvement in the judicial process may take several different forms depending upon the goals of the particular group. However, two principal tactics stand out: involvement in test cases and presentation of information before the courts through "amicus curiae" (Latin, meaning "friend of the court") briefs.