I think the context here was that it would be a humiliation for Trump to run and he would lose by a wide margin. Oliver would find it funny to watch him try. Guess that didn't age too well...

I don't know how people can watch him... I've tried, I tried to watch and be impartial and give him a fair shot but man I couldn't get past a few shows before wanting to rip my eyes out and jam nails in my ears...