Conversation so far:
what powers does congress have under the constitution
Congress has authority over financial and budgetary matters, through the enumerated power to lay and collect taxes, duties, imposts and excises.
What is the definition of excises?
An excise, or excise tax, is any duty on manufactured goods that is levied at the moment of manufacture rather than at sale.

Question: who defines the powers
Self-contained rewrite: who defines the powers of congress