The primary duty of the legislative branch of government is to introduce, review and pass legislation. The legislative branch of the government is the only branch of the government that can pass new laws. This is done through the utilization of a committee system, which divides the members of Congress into smaller groups that are responsible for reviewing legislation and determining whether to introduce it to the floor for debate.
The Necessary and Proper clause was intended to allow Congress to decide whether, when and how to legislate for "carrying into execution" the powers of another branch, and at the same time intended to respect and reinforce the principle of separation of powers.
