The exact scope of the Commerce Clause is actually one of the classic questions of US constitutional law. Court interpretations have gone back and forth over th

The exact scope of the Commerce Clause is actually one of the classic questions of US constitutional law. Court interpretations have gone back and forth over the years; currently, things are a bit muddy because members of the Supreme Court have a tendency to expand or restrict the clause to suit their own ideologies (i.e., Scalia believes that a federal ban on marijuana can apply even to marijuana which never crosses a state line, because he doesn't like marijuana; he has a very different and arguably conflicting opinion on gun regulations, though, because he likes guns).