Congress has limitless power? BS.
The Constitution gives Congress explicitly enumerated powers, not unlimited plenary powers.
If Congress had endless power, then why would the Framers have bothered to list its powers in the Constitution, one by one?
Since the beings of the Republic, arguments have been made, and accepted, that some actions of Congress exceed their delegated powers and are unconstitutional.
“The Constitution gives Congress explicitly enumerated powers, not unlimited plenary powers.”
Unless you can identify the limitations placed upon the Congressional power to declare war, that power is a plenary power. Read the definition of plenary.