Sen. Kamala Harris, D-Calif., appeared to call President Trump a "joke" while responding to his son questioning her sense of humor on Friday. The exchange surfaced after Trump Jr. tweeted the question: "Why is @KamalaHarris the only person that laughs at her jokes ... always way to [sic] long and way too hard?" He added that she was the "most disingenuous person in politics ... after Hillary," a reference to his father's former opponent, Hillary Clinton. Harris responded with an apparent attack on his father. "You wouldn’t know a joke if one raised you," she tweeted. Trump Jr. shot back...