Well I watched their convention and I heard a lot more about the Constitution than pot. I heard a lot more about the Constitution than I expect to listening to the Republican convention this September.
Think about that for a second.
The problem is that most Americans don't care about the Constitution any more.
And most of the blame for that (in my opinion) is because it has been gutted, not by any President or Congress, but by judges, from the local level all the way up to the Supreme Court. They have gutted it and allowed it to be gutted.
People see their representative bodies passing and enacting laws, only to have them negated by the courts, and made-up laws and made-up rights being imposed on them by the courts under the guise of constitutionality.
Note: I am not a Libertarian.