Donald Trump struggled through another rally speech marred by mumbling and slurring in Milwaukee, Wisconsin rally on Tuesday — and his critics were delighted. “Joe Biden is forming granting mass–thinkit,” Trump meandered in a section of the speech, with an excerpt of the video quickly spreading on line. The mumbling led to his foes, like the Republican Never Trumpers at Lincoln Project, to anticipate “the debate should be fun.” Want more breaking political news? Click for the latest headlines at Raw Story. At another moment, Trump mispronounced citizenship by calling it “citizensip.” Trump we…