Nonetheless, members of Congress sometimes serve as agenda setters. They may do so to challenge a president of the opposing party, to gain a reputation as a power broker themselves, or indeed to place on the national agenda as issue they feel requires attention. Committee chairs enjoy a special advantage in congressional agenda setting; they control the agenda of their committees' hearings. And these hearing offer the best opportunity for congressional involvement in agenda setting. Congressional staffs- committee staffs, staffs of the legislative leadership, and aids to individual legislators- often play an important role in bringing issues to the attention of the their bosses.