That’s not what he’s alleging. He’s alleging that some of the police there were not USSS, but instead were Homeland Security Investigations officers drawn from field offices to bolster site security.
No shit.
Hawley’s basically just exposing his ignorance about how protective security at large events happens. There’s a very finite number of officers specifically trained in close protections, and almost universally all that’s needed at such events is a lot of police presence. Investigative officers will get told to throw a suit and their gun on and provide site security. That’s utterly normal. In the various videos of things going sideways in Butler you see a number of them, including several who help escort Trump from the dais to his truck, and some of whom get in a support vehicle to help provide security when he arrived at hospital.
The president himself could be at an event with his full USSS security package, and outside of his immediate vicinity there would be various federal officers and local police all over the site who aren’t close protection trained and are relying on their normal training to be vigilant and engage threats. Since most federal agents aren’t out on the road dealing with dangerous situations very much, that can look fairly rough. Par for the course though.