There isn't any other way to read it: "If my guy doesn't win, then it is false, and elections don't matter."
The unquoted portion of the screed consists of a lot of delusional notions about how VP Harris couldn't possibly win and the Democrats are already cheating, etc. Trump, despite his claim yesterday, is not loved by 75% of the people. He is not inevitable and not invincible. Until the mask came off at the debate, President Biden had reasonable shot of winning. Many prominent Democrats, including the VP, also would have reasonable shot of winning.
The difference between me and this anti-democratic sub-stacker is that I also think Trump has a reasonable chance of winning as does VP Harris have a chance. The majority of Americans recognize this.