For a good idea what can go wrong with referendums, take a look at my state of California.
People keep voting for referendums that mandate that the state spends more money, and also for ones that put strict limits on taxes.
Now we have a state that's going broke because it cant pay its bills.
Aside from that, there really is nothing in the Constitution that allows issues to be decided by the popular vote - having watched the budget crisis
here, I am glad.