Donald Trump gave a rally on Saturday in which he made multiple verbal slip ups that left online observers scratching their heads. Trump spoke at an indoor rally in Prairie du Chien, Wisconsin, where at one point he called Vice President Kamala Harris “a mentally disabled person.” At another point in the rally, Trump said most people don’t know what phone apps are, leading to widespread mockery. But Trump also had several misfires at the event, opening himself up for even more mockery on social media. Want more breaking political news? Click for the latest headlines at Raw Story. ALSO READ: Dy…