 AND WITH J.D. VANCE, IT IS HIS BIG CHANCE TO REALLY PRESENT HIMSELF NOT ONLY TO THE PARTY, BUT TO THIS BIG AUDIENCE THAT WE'RE EXPECTING TONIGHT FROM MILWAUKEE. HOMELAND SECURITIES INSPECTOR GENERAL IS NOW INVESTIGATING THE SECRET SERVICE'S HANDLING OF SECURITY AT LAST WEEKEND'S PENNSYLVANIA TRUMP RALLY. CBS'S CHARLIE DEMAR.