They genuinely believe they're identifying and defeating a mass fraud conspiracy. Fox News and worse have done a phenomenal job of building echo chambers that convince them the libs are a bunch of cheating charlatans and that's the only reason they have the popular vote.
Their worldview is completely wrapped around this and so anything to the contrary is ignored as evidence of the conspiracy.
Ironically, this is the "sell the shovel" situation from the gold rush, but in Gold's favor this time. Chip rush!