There is a difference between how the two speak. Trump's language is the language or someone who lacks an education, but who maintains fluency. The way Biden talks reveals the opposite - he sounds like an educated man who's struggling to put his thoughts into words, he gets lost mid-sentence and doesn't always recover.
I'm not trying to say that one is better than the other, but you could definitely make cruel jokes about both flaws. You know, "bigly (big league) believe me, it's true, it's true" vs "turn on th-the radio, keep the record player on at night, MAKE SURE THE KIDS HEAR WORRRRRDS"