The distinction is profound and underlies the difference between the American system and all other systems of government.
While what you say is valid, it is nonetheless incorrect. I recommend you revise your position.
The method the founders used to limit the power of government was to enumerate congress's areas of legislation. The founders did not enumerate areas where Congress could not legislate. Instead, the founders enumerated the only areas where Congress could legislate. This means that if the Constitution does not specifically say Congress can, then Congress cant.
Presenting the Constitution as telling the government what it may not do is a problem because liberals will take you at your word. You may say some legislation is unconstitutional and a liberal will say you are wrong because they cant find anywhere in the Constitution where it says the Congress cant legislate that.