When vote counts suddenly stop and then overnight the opponent starts surging, people tend to assume foul play is at hand. This is how it happens everywhere where an actual authoritarian cheats to stay in power, for instance: https://twitter.com/ajplus/status/1186630753523818502. For you to not understand something like this is grounds for people to question the validity of elections all over the world means that you don't understand much about the world, let alone what's happening in your own country. And I speak about this as a non-American who's simply watching it. You're being brainwashed by your media into believing things that aren't true.