New York : US President Donald Trump has asserted that California Senator Kamala Harris would be former Vice President Joe Biden's "boss" if the two Democratic Party candidates defeat him and assume the nation's top jobs. After repeatedly questioning the mental acuity of Biden, who is to be the Democratic Party's presidential candidate, Trump asked on Monda:, "Do you want to crush our economy under the crazy socialist policies of sleepy Joe Biden and his boss Kamala Harris?" Harris, Biden's running mate, is to be the party's vice-presidential candidate. Speaking at a rally in Oshkosh, Wisconsin, Trump referred to Biden's mental powers and said: "He's shot, he's shot." After mentioning instances of Biden mis-speaking and his refusal to hold open press conferences, Trump made the dig about Harris and also House Speaker Nancy Pelosi being his boss. If elected, Biden who will turn 78 in January 20121 would be the oldest person to assume the presidency, while Harris would be 56. To needle the Democrats in his usual style, Trump stopped at the Oshkosh airport, about 100 km from Milwaukee, the official venue of the Democratic National Convention, which is being held remotely, and held a rally of a few hundred people in front of his Air Force One jetliner. After saying Harris would be the "boss", Trump then turned on her saying she had left the Democratic Party primaries - the internal election - "in shame" with her poll numbers going from 14 per cent to 2 per cent. He called her "mean" and "angry". Biden was a "trojan horse for socialism," who "has no clue, but the people around him are tough and they're smart", he said, adding: "They're mean and they're angry like her." Trump raked up Harris's criticism of Biden for racial insensitivity when she was running against him for the party nomination. "Nobody treated Joe Biden worse than Kamala," he said. "She was worse than anybody on (the debate) stage. Nobody treated him worse or with less respect. She had no respect. All of a sudden she's now saying he's wonderful. She didn't feel that way a little while ago." Trump said that if Biden and Harris won, "China will own the US". He claimed that "time and again, sleepy Joe Biden put China first and America last" and then brought up the business dealings of Biden's son Hunter with Chinese companies. Hunter Biden "had absolutely no experience (but) walked away with one and a half billion dollars to manage, that's millions of dollars a year", the President asserted. Trump said that crime would shoot up in the US because of the movement backed by the Democrats, under a Biden-Harris administration. The movement against police brutality and racial injustice has sometimes turned violent and into demands for disbanding police or cutting finance for police.