If it was JFK Jr it would be a clear QAnon conspiracy reference, but with it being Sr, I'm not sure. My guess is it's either a thinly veiled assassination "joke", or just some empty-headed comparison thing.
Or maybe not a "joke", but "the government's going to kill this great president just like they did with Kennedy!"
The food here is terrible. My steak was so tough it attacked my coffee and the coffee was too weak to defend itself.