I think plenty of them know it's a lie, they're just going along with it. It was a hail Mary attempt to keep Trump in power. Didn't work, but it still has advantages for them moving forward.
Of course there are also some true believers. I've met them irl. They're unwell.
See my response to Troks. We need to give these people an out. They need to return to society and begin the healing process.