The US federal government does not, but they are rather common in US states. The US federal government was structured with its direct constituents as states, no

The US federal government does not, but they are rather common in US states. The US federal government was structured with its direct constituents as states, not citizens, and while that has evolved a bit over the years, it still is reflected strongly in its structures (Constitutional amendments must be ratified by a kind of referendum, but it is a referendum of state legislatures, not citizens.)