No I am not. First the General Welfare Clause is the entire list of enumerated powers along with the preamble to Art. 1, sec. 8. Second the supremacy clause basically says that if the states try to legislate in the enumerated powers, they are wrong, because the states ceded their authority to the feds in those areas. Lastly, the Commerce Clause is nowhere near as broad as it began to be interpreted as seen in the Obamacare case.