I can't quite tell if the street-level rubes see this -- it's always difficult to tell -- but this "everything is rigged against us, everyone else is corrupt" dogma is simply being deployed to provide an excuse for MAGA leaders to follow through on their plans.
They figure the country is all but lost, and so it's time for the Hail Mary: Bring down our institutions at all costs, and eliminate any national agency that can hold these people accountable. As long as the street-level rubes are kept at this level of misguided rage, this could work.
"Everything is rigged, everyone else is corrupt, we're doing God's work against Satan, and anything we do is justified". That's the GQP platform now.