The main reason why this has not happened is that there have been and still are serious concerns about the advisability of direct democracy. The Framers of the Constitution would not have wanted a referendum because they wanted to keep the government somewhat distanced from the people. There are still many people who feel that legislators should be the ones to make the decisions because they are more likely to be well-informed on the issues about which they are voting. It is for this reason that only about half of the states in the country have a referendum process. The main factor, then, is the fact that not everyone in the country thinks that more direct democracy is a good thing.