Question: Where does congress draw its constitutional powers from?
Disambiguated questions and answers: question: Where does congress draw its constitutional enumerated powers from?
Where does congress draw its constitutional implied powers from?
Where in the Constitution does congress draw most of its constitutional powers from?
answer: the Constitution
Necessary and Proper Clause of the Constitution
assumed to exist
Necessary and Proper Clause
Article I
Natural Questions answer: the United States Constitution (from the Wikipedia article "Powers of the United States Congress")