 Former President Trump's vice presidential running mate has introduced himself to America. Senator J.D. Vance took the stage at the Republican National Convention last night. Tonight, former President Trump will address the gathering. Senator Marsha Blackburn, 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 last weekend.