There needs to be something like the federal equivalent of a referendum. I think with that, it would be possible to get rid of the patriot act and legalize weed, both of which seem to have popular support but zero chance of majority of representatives backing because they don't want to be liable for the worst-case corner-cases in the aftermath.
We are constantly voting in primaries and general elections. We vote in federal elections every two years, state elections generally at least as frequently, though often not in federal election year. We vote for mayor and city council and insurance commissioner and Secretary of State and county commission.
We don't need a referendum, we just need to choose representation that wants the same things we want. (Alternate formation: Americans do not want these things as much as some of us think they do.)