In the past presidential election in the U.S., there were 22 candidates, including a socialist, a libertarian, borderline theocrats, establishment politicians, and whatever you classify Trump as.

There's usually a ton of competition, but most people simply don't care. Ask people who they voted for in the last primary for state legislator, and the reasons they voted for them over their opponents. In my experience, people often have a hard time remembering who they voted for the next day, and it's extremely rare for someone to have a good reason why they voted for them.

I've seen a lot of reformist candidates run against corrupt incumbents and lose. It's depressing, but even more so when you see that almost no one bothered paying attention to the race. And then you see the same people complain later - "Why's the government so bad? How come there's no choice and all candidates are the same?"