The net result of the 30's era interpretation of the commerce clause was to give the federal government control over any material object you might posess, on the grounds that it might someday be interstate commerce. The founders envisioned a federal government with strictly limited powers. Do you think that if this is what they intended, they'd have been a little more specific, and that their writings in the Federalist Papers and would have addressed this issue in more detail?
Granting of authority to the federal government entails more than declarations of a "self-evident need". That's why we have provisions for amendment.