Garbage. If it applies it to drugs, then it also applies to health care, the environment, and just about anything else Congress wishes to legislate. Read Walter Williams' piece on constitutional contempt and learn something:
Regarding the "general welfare" clause so often used as a justification for bigger government, Thomas Jefferson said, "Congress has not unlimited powers to provide for the general welfare, but only those specifically enumerated." James Madison said, "If Congress can do whatever in their discretion can be done by money, and will promote the general welfare, the government is no longer a limited one possessing enumerated powers, but an indefinite one subject to particular exceptions."
-snip-
Congress is not alone in its constitutional contempt, but is joined by the White House and particularly the constitutionally derelict U.S. Supreme Court.
http://economics.gmu.edu/wew/articles/07/congressionalconstitutionalcontempt.htm
Whenever someone frames an arguent in the form, “If it applies it to X, then it also applies to Y,” their argument is specious.
The suitability of the death penalty applies to murder; it does not apply to littering.
It is appropriate for the government to criminalize drugs; it is not appropriate for the government to pursue socialist policies and programs.
Look at what you’re equating: prohibition of drug use with the imposition of socialism. It’s batty on the face of it.
You just refuse to get it: The prohibition of drugs is not “unlimited powers,” nor does it constitute “whatever in (congress’s) discretion.”
The fundamental dishonesty in the arguments your side has been attempting to make, though, is that you don’t merely want to argue that the federal government can’t prohibit drugs: your ultimate aim is to force upon us the view that no government has the authority to prohibit drugs. These references to the 10th Amendment are hypocritical in the extreme.
Much of our drug problem has actually been attacks on us by foreign powers — the USSR, for instance — and by various terrorist and communist groups that are our enemies. Attacks across our national borders, aided by the fifth column here at home.
Not only is it appropriate that the federal government should address a problem that crosses our national borders, it is utterly beyond the powers of the states to do so.
The fact that some of our government agencies have become jack-booted Nazi thugs is a problem, but it is a separate matter from the propriety of drug prohibition.