Because it's a set up and a distraction. Every election is 'the most important election' or 'the last chance to defend democracy'. Meanwhile Democrats get further and further right, even moderately left wing candidates are dragged, destroyed and disgraced, and it's a bigger fucking circus every time. Your 2 party system is beyond broken, it's working exactly as calculated and intended by the corporate interests that have completely captured and infiltrated it. You go ahead and vote but don't fool yourself into thinking anything is going to change for the better no matter what happens.