What is the necessary and proper clause?

Article 1, section 8, clause 18 of the construction; one of the powers of congress that allows them to make any laws that are necessary and proper for carrying out their other powers. Also called the Elastic Clause. 

Often called the "elastic clause", the necessary and proper clause simply states  that the Congress has the power," 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  orOfficer thereof. 
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