The word would get around that Trump isn't making this stuff up and no need to research it on the Internet.
I doubt television stations would run campaign ads with death scenes, but certainly they could be put on the internet.
Expanding on that idea...
Trump needs a big screen behind him at all times. Images on the screen should correspond with what he is talking about. For example, if he talks about chaos in the ME, the screen can be running an easily visible crawler about 400,000 dead in Syria, and showing images of destruction in Alleppo (or wherever)), maybe that poor Jordanian pilot just before the flames begin, weeping widows, and so on.
This is not for the benefit of the crowds, it is to get caught on MSM cameras, so they can’t avoid the images.
Sorry if that blocks out a few supporters, but there is more at stake...