No kidding. I knew this back in the mid-Seventies, contrasting their treatment of Ford with Carter. The execrable and un-funny Chevy Chase just lived on his Ford portrayals as a bumbling boob, contrasting with the clever and sometimes funny (but rarely derogatory) portrayal of Jimmy Carter as a call center guest for drug users...
The double standard was evident even then. And it became far worse with Reagan.
I can't remember, did SNL make funny of Carter being attacked by a killer rabbit?