Khan asked what Trump had sacrificed in response to Trump calling for a ban on Muslims immigrating. His point was that Trump's policy would tarnish all Muslims despite the sacrifice that some Muslim families in the US had experienced. So having a similar exchange with Hillary (and Bill?) would look a little more odd:

Trump: No Muslims can enter the country!

Khan: We are Muslim and our son died a hero in battle, why would you make this policy?

vs

Hillary: We should stop terrorists from entering the country.

Khan: OK.

or

Bill: I like these balloons dropping onto stage.