The only thing to do is just stare at her with no expression on your face, or maybe an expression of mild confusion — like you’re thinking to yourself: “Am I at a presidential debate or in a hospital ward?”
Silence is Trump’s friend.
If Hillary coughs he needs to stay calm and relaxed, try not to react, and he should say nothing.
He wants everyone to hear her cough—as long as it takes.
The moderator will panic and try to interrupt—probably with a question for Trump.
Trump needs to counter with: “My opponent did not have an opportunity to complete her response to the previous topic. I want to give her that opportunity.”
Then he needs to shut up...
and stay quiet...
and wait...
and wait...
and wait...
let the camera and the audience go to her...
and stay quiet...
It will be the ultimate...silent close.
(The old salesman trick—ask your question and then quietly wait for the answer..as long as it takes..let everyone be uncomfortable...let silence be your friend.)