 vice presidential running mate has introduced himself to America, Senator J.D. Vance, taking the stage at the Republican National Convention in Milwaukee. Tonight, it's former President Trump's turn to address the convention delegates. Senator Marsha Blackburn is among those demanding the resignation of Secret Service Director Kimberly Cheadle. Blackburn says she is appalled the Secret Service was aware of a threat before former President Trump took the stage in Butler, Pennsylvania, where he was shot and wounded.