<P> Congress also has the power to establish post offices and post roads, issue patents and copyrights, fix standards of weights and measures, establish courts inferior to the Supreme Court, and "To make all laws which shall be necessary and proper for carrying into execution the foregoing powers, and all other powers vested by this Constitution in the government of the United States, or in any department or officer thereof ." Article Four gives Congress the power to admit new states into the Union . </P> <P> One of the foremost non-legislative functions of the Congress is the power to investigate and to oversee the executive branch . Congressional oversight is usually delegated to committees and is facilitated by Congress' subpoena power . Some critics have charged that Congress has in some instances failed to do an adequate job of overseeing the other branches of government . In the Valerie Plame Wilson episode sometimes known as the Plame affair, some critics, including Representative Henry A. Waxman, charged that Congress was not doing an adequate job of oversight in this case . Other critics charge Congress was lax in its oversight duties regarding presidential actions such as warrantless wiretapping, although others respond that Congress did investigate the legality of decisions by President George W. Bush involving such matters . </P> <P> Congress also has the exclusive impeachment power, allowing impeachment, trial, and removal of the President, federal judges and other federal officers . </P> <P> Among the powers specifically given to Congress in Article I Section 8, are the following: </P>

What is not a power granted to congress in the constitution