Trump should expect any dirty tricks from Democrats
But at this moment there is a chance that democrats will try to sabotage elections. The voting in US is largely provided with electronic machines. It has no pepper trail. So, whoever programs those machines can determine the vote outcome. And nobody will ever know. Unless Trump has some kind of experts, who can ensure that the voting machines are programmed correctly. I suspect that machines will be programmed to vote for Hillary, because some many republican political establishments are opposed to Trump. If he relies on them, they will cooperate with Hillary’s people and program the machines such as Hillary wins. There is no paper balance to recount it. This is the way a lot of elections have been stolen in recent years. This may happened again.