Donald Trump has in the past ridiculed President Joe Biden for misspeaking, but on Saturday the former president became the one who was subject to mockery after making numerous verbal slip-ups at his Wisconsin rally. Trump over the weekend spoke at a rally in Mosinee, Wisconsin, where he at one point suggested that people in their 80s are too old to be able to be held accountable for documents they have signed. Trump is 78, and running for a four-year presidential term. But it wasn’t Trump’s claim about age and its potential effects that caught the attention of most of his critics. Want more b…