What kind of government does the US have now?
The US has a system that is federalist, which defines the way power is shared between the central government and the states. It also has a system that is a mix between a republic and a democracy, which explains the amount of say that people have in the government.
The Canadian government does not requires US residants to present a passport when entering Canada and the US government does not require a passport for its residants when returning to the US. However, the US government does now require passports for Canadians entering the US but they are not required by the Canadian government on the return trip.