Of course a jamming device could be installed, but unfortunately there would be hundreds of legitimate other signals around the area as well.
I’d be surprised if she were receiving an encrypted signal.
It would be nice to find her signal and make it known:
[Mr. Trump think he has a point] Mr. Trump think he has a point. [But I disagree with everything he just said] But I disagree ... with ... [with everything he just said] with everything he just said.
Just scan both of them head to toe for metal as they get on stage.