I’m in Maine and listened to Howie’s radio show from 3 PM to 7 PM Eastern time.
Howie and Grace were doing their radio show live from a studio in Manchester, and decided to stay there and do their show rather than go to the rally.
I think it was not possible for them to do the radio show from inside the venue, and they would have had to have shown up hours earlier, when the show was already on the air.
It was either go to the rally or do the radio show.