You are absolutely right, Bob, and that is why the current grassroots organization Local Revolutions is doing very important work.
The starting point is the law, and the law says that governments must use the better system, unless given exception in the US Constitution.
The Federal and State governments are given exception indeed, but the local level of cities and counties are out in the wide open and must use the better voting system.
The good news is therefore that the law is already on our side. The bad news is that these are baby steps. Yet baby steps taken are always better than steps not taken. We have to get rid of this two-party behemoth.
At the local level, we don't vote on party lines, but we are using the winner-take-all path in district or at-large elections.
Once a city has Proportional Voting in place (all voters can point to the representative they wanted sitting in a seat, not just the winners), then the wool will come off our eyes and we will realize we were kept in jail with good cop/bad cop all these years.
The Founding Fathers never described a two-party system and it is at the local level that this becomes obvious; we are entitled to have Proportional Voting in our cities and counties. No government is allowed to deny or disparage our rights in this respect because there is nothing in the US Constitution that gives that power to our local governments. Rulings in the past have made it clear already that local governments MUST use the better system and cannot put a system in place that discriminates such as district voting.
Come join Local Revolutions grassroots organization (always in bold because it is bold to take on your own government).