Congressional Hearings contain a wealth of information related to a bill. They may also contain the dramatic back and forth question/answer as part of an investigation Congress is carrying out. Suitible for all levels of research, Congressional hearings can be found though a variety of ways at UC Berkeley [Numbers in brackets denote Congressional Session]:
Indexing and full-text access for publications of the United States Congress such as hearings, committee reports and prints, CRS reports, as well as executive branch documents. (Congressional Publications) [dates vary]
One stop shopping for all U.S. congressional publications. Provides indexing and abstracts of congressional publications back to 1789, including the full-text of published Congressional Hearings (1824-present; unpublished hearings until 1979), Committee Prints (1817-present), Congressional Research Service (CRS) Reports (1916-present), Congressional Record and its predecessor titles (1789-present), U.S. Congressional Serial Set and Maps (1789-present), Executive Branch Documents (1789-1932), Presidential Executive Orders and Presidential Proclamations (1789-present), and Legislative Histories (1969-Present; earlier legislative histories are available via ProQuest's Legislative Insight).