All legislative Powers herein granted shall be vested in a Congress of the United States, which shall consist of a Senate and House of Representatives.
The framers of the Constitution separated the powers of government into three branches, granting legislative power (the power to pass laws) to Congress, executive power (the power to administer the laws) to the president, and judicial power (the power to interpret and enforce the laws) to the courts. The unique and limited powers of Congress are contained in Article I.
The framers believed that this separation of powers would ensure that no one person or group of persons would be able to create, administer and enforce the laws, and that each branch would be a check on the power of the other two branches. Under this scheme, Congress cannot give its lawmaking powers to the executive or judicial branch. The courts are charged with ensuring that the three branches act independently and do not overreach their delegated powers. But in some instances, two branches of government are required to work together. For example, the Senate must approve the president’s appointments to the U.S. Supreme Court, and the president has the power to veto acts of Congress or to pardon convicted criminals.
Another important principle is contained in Article I, Section 1: The federal government’s power is limited to what is written in the Constitution. These are known as “enumerated powers.” If the Constitution does not specifically give a power to the federal government, the power is left to the states.
Article I, Section 1 also requires that Congress be bicameral, that is, it should be divided into two houses, the Senate and the House of Representatives. At the time the Constitution was adopted, several states and the Continental Congress had only one lawmaking body. The creation of two legislative bodies reflected a compromise between the power of the states and the power of the people. The number of seats in the House of Representatives is based on population. The larger and more urban states have more representatives than the more rural, less-populated states. But the Senate gives power to the states equally, with two senators from each state. To become law, any proposed legislation must be passed by both the House and the Senate and be approved (or at least not vetoed) by the president.