Ok so the theory goes that the GOP is secretly occupied by the most vicious Dems, the Dems control both parties.
During the civil war, it was the northern Republicans who wanted to abolish slavery and adopt the most leftist posture. The democrats in the south seceded.
After losing the civil war, the Dems vowed to wage a secret forever war in the congress. They did this by infiltrating the GOP and gradually steering it towards rabid facism which, by comparison, made the Dems look left wing. The Dems could then push and pull the center wherever fit their aims and narrative. They could enact and enforce the most racist and classist policies by proxy of the GOP, and then 'fail' to prevent them as the Dems.
By dominating positions of power within both parties, they could gatekeep access to both. Shuttle the hateful extremists to the GOP, funnel the ineffective, flaccid liberals to the Dems. That's why the Dems have been the most vocal opponents of effective leftists.
The GOP needs an aggressive coup to return it to its leftist socialist roots, a party who isn't afraid to meet violence with violence again to counter the democrats' subterfuge and drag the nation back towards its liberal, egalitarian and class-concious destiny.