I think Democrat politicians are more disrespectful of Republican Presidents--because they know they can get away with it without being jumped on by the media (which shares their disdain). Obama was particularly egregious in the 2008 campaign with his sneering comments about "old Bush" (meaning the incumbent President). Probably Clinton was just as bad but I don't recall specifics from 1992.
When Hillary was in the Senate she flashed a newspaper front page that had in huge letters "Bush Lied" for all to see.
Meanwhile other Democrats were calling him a chimpanzee, and so on.