DOUGLAS GINSBURG, Federal Judge, U.S. Court of Appeals, D.C. Circuit:
The two parts of the Congress are the Senate and the House of Representatives. Why two bodies? The answer may surprise you: to make it twice as hard to pass a law.

Protecting liberty was the paramount goal of the Framers of the Constitution. They were more fearful of passing bad laws than a failing to pass good laws. To become a law each bill has to go through both chambers. The Congress is designed to ensure laws do not pass without broad support.
The Framers also drew distinctions between the two chambers. Several powers are reserved solely to the Senate. The president’s ambassadors must be confirmed by the Senate. Likewise, most senior officials in the executive branch, including cabinet secretaries. And, as I know firsthand, the Senate confirms judges nominated by the president to the federal courts.
The Senate also must approve any treaty negotiated by the president – though lately presidents of both parties have skirted the Constitution by calling a treaty an executive agreement, and not seeking Senate approval. Finally, the Senate has the sole power to try a federal official whom the House has indicted, the term here is impeached.
That’s a lot of responsibility for the Senate. What about the House? The Framers gave the House of Representatives only one special power, but it’s the greatest of all: the power to tax. Every spending bill must originate in the House – the body closest to the people.