But the answer is not to get rid of the fillibuster. it is simply to say that fourty percent of one house or the other can propose a referendum. I proposed this in the second sentence of my second post in this blog. Note, that if there are several related proposals they would be resolved by approval voting.
And Congress can do this, I believe, without a Constitutional Amendment--although that would make it bullet proof. The United Supreme Court has required that Congress provide some standards in delgation of powers. And in Clinton versus City of new York, the Supreme Court stopped a line-item veto to the President. The question is whether this proposal, a delgation back tot he people is an unconstitutional delegation of powers. I would argue that there is a very definite standard, simply counting the number of votes of the populace.