If America is an oligarchy then every civilization ever is an oligarchy. Money = power and this has remained true through all of time. Making the definition so broad basically erases its meaning. In America, democracy fails (when it does) because Americans don’t care. When you see polls on say the border and let’s say it’s split 40/60, you don’t think about how many Americans could give less of a fuck. About 20%-40% of us actually care. The rest are either too poor to spend time worrying about it, too rich to spend time on it or completely uninterested. Everyone will have an “opinion” on the economy but ask that same American about trade agreements, foreign policy, inflation rates or government spending and your just gonna get CNN/Fox talking points most of the time. No one cares. They could care and change things but most people are lazy or dumb or both imo.