How would the secret service deal with this? Would they be allowed to be armed on prison grounds?
No one really knows.
For some time ex Secret Service agent Dan Bongino has said the prisons would be totally disrupted to give agents logistics to protect him. They are under obligation to set up agents close and far wherever Trump goes, including if in prison. Really difficult to do.
There is a threat of a bill already brought up in Congress to deny protection to “any” ex President. Thus, setting him up for getting killed.
Another is to use an abandoned prison (apparently two of them have already been scouted out) re-opened for just one prisoner-—Trump.
Another is a “holding cell” made up of a court building room down the hall which will de declared a “prison” with Trump held for a few days.