The US Constitution was artfully constructed to avoid such tyranny of the majority via a Republic checked and balanced by various mechanisms (Electoral College, Bill of Rights, Separation of Powers, etc).
Old people on fixed incomes move the hell away from jurisdictions where the moochers of the FSA have a majority or plurality.
I'm interested to know where you draw the line between people having rights and people having the authority to make laws that affect other people's rights.
It's a difficult question because the answer varies depending on local conditions.
The federal authority must be strictly libertarian (IE minimally statist).
The 50 States and their constituent regions/counties/municipalities/school districts/homeowner associations are laboratories of democracy which experiment with the trade offs between security and liberty to find the optimum balance and compete in the marketplace of jurisdictions to acquire citizens to pay taxes and consume their services.
I choose to live in a place where economic freedom is relatively low but personal freedom is relatively high. It's not a perfect fit, but the weather is really nice!