We saw the blue spikes in November 2024 at night. They tried to cheat. Mail in voting might swing lefty but it doesn't swing 4:1 lefty without real fuckery. The thing is, they couldn't overcome the Red Wave. Too big to rig, as they say.
That's why they're so pissed. They cheated, they rigged the election... and they still lost. In their minds, the only cope they can come to is the idea that Trump must have cheated better than they cheated. This works a few things on the cognitive dissonance: It makes their own cheating ethical ("we have to cheat too to make it fair" is something I heard as early as 2012), it gives them an excuse to consider Trump illegitimate ("he rigged the election... better than we did"), and it gives them justification to handwave away them losing every single observable metric in the election. ("He isn't that popular he cheated, real people don't like him only racists in the flyover states and look these EX-MAGA are even saying he's horrible.")
Based Dilbert Merchant calls this the "two movies, one screen" effect. Where due to various cognitive dissonances and marketing and epistemic closures two people can see the exact same data and come to two completely different worldview conclusions of it. In the left's worldview, Literal Hitler Stole an election better than they could and is tard-raging through the government, literally dragging poor innocent fedboy glowies away from their desks to be shot in the street for the crime of disagreeing with him.