Fun challenge, I'll try to tackle it for kicks!
What you have currently is a joke, with a setup and punchline. You can either try to maintain that structure with a setup word, transition verb, then punchline word structure... Or you can abandon the joke and repackage the subtext/implication of the joke as bold, explicit text. The first would require great cleverness. The second would be easier and clearer.
Example A: Joke Format (Setup, Transition Word, Punchline) - "Clowns Know More" or "Clowns Do Work"
That is kind of vague about what you are referring. It might take many drafts to get close to something that works well.
Example B: Abandon metaphor, replace subtext with text - "Trump's A Chump."
I first thought of Trump's A Fool but I figure rhyming is catchier.
To be honest, I think a joke like this is fine as is, but doesn't lend itself to a movement-defining rally call either way. It's best used the way you wrote it as a hook to a speech talking point, or during a one-on-one conversation with an engaged individual, rather than a crowd call-and-response. You can then follow up with "Trump's a chump" after you have their ear, as a way to hammer home your point and compel them to adopt this view.
To be fair, Trump attended a college, so you need to be ready to demonstrate he never studied, is lazy, and illiterate/ignorant.
I do think giving him the moniker "Chump Trump" to deride his stupid choices would help distance people from him. MAGA loves mocking others, hate being mocked, and deride those who fall victim to mockery.
Consider having a QR code for that URL handy if you are engaging folks 1-on-1 and taking this angle as your tactic! Be wary of using this tactic with folks who may hate professors, though. If they personally have been derided by educators and hate higher education, this tactic may backfire. With those folks, talk about how Trump lacks "common sense." You should profile the listener and make an educated guess which way to take it.