The structure of the United States Congress with a separate House and Senate is complex with numerous committees handling a disparate array of topics presided over by elected officers. Some committees manage other committees. Congresspersons have various privileges to help the presidents serve the national interest and are paid a salary and have pensions. Congress formed a Library of Congress to help assist investigations and developed a Government Accountability Office to help it analyze complex and varied federal expenditures.
Most congressional legislative work happens in committees. It is neither expected nor possible that a member of Congress be an expert on all matters and subject areas that come before Congress.Congressional committees provide invaluable informational services to Congress by investigating and reporting back in regard to specialized subject matter.
While this investigatory function is indispensable to Congress, procedures such as the House discharge petition process (the process of bringing a bill onto the floor without a committee report or mandatory consent from its leadership) are so difficult to implement that committee jurisdiction over particular subject matter of bills has expanded into semi-autonomous power. Of the 73 discharge petitions submitted to the full House from 1995 through 2007, only one was successful in securing a definitive yea-or-nay vote for a bill on the floor of the House of Representatives. Not without reason have congressional committees been called independent fiefdoms.
In 1931 a reform movement temporarily reduced the number of signatures required on discharge petitions in the U.S. House of Representatives from a constitutional majority of 218 down to 145, i.e. from one-half to one-third of the House membership. This reform was abolished in a 1935 counterattack led by the intra-House oligarchy. Thus the era of the Great Depression marks the last across-the-board change, albeit a short-lived one, in the autonomy of House standing committees. On strategy for an enduring reform in the system of semi-autonomous committees see the citation.
In the course of committee work, members will often develop personal expertise on the matters under the jurisdiction of their respective committee(s). Such expertise, or claims thereof, are invariably cited during disputes over whether the parent body should bow to obdurate committee negatives.