Which has always been true of many presidential activities under Obama, Bush 43, Clinton, Bush 41.........Giving an official speech ( like a graduation ceremony) during an election campaign is very political but paid for my taxpayers using many federal employees.
My understanding is that, the power of incumbency can be used within limits. Trump's turning the COVID briefings into campaign rally because people weren't going to his actual ones was just the beginning. Now We, the People, see him using the White House as his personal abode to use as he pleases.
The problem with breaking rules like this is that it's only a matter of time before a Democrat does exactly the same thing. Remember all the shouting in Congress about not using the "Nuclear Option"? That was broken and, in this toxic environment, will never be corrected. It's done. Now the Hatch Act is done unless Congress does something about it...which they won't.

