We need more information about the shooter and his motives. We know he was Muslim and an American. This wasn't a "usual" Islamic terrorist attack. If it was, and especially if he was foreign-born, it would help Trump a lot. But this was an attack on a gay nightclub during Pride Month. It's almost certainly a hate crime. This tragedy cuts several ways, including on assault weapons.
It only cuts one way. The word Muslim is key and thats the only word voters will remember. Honestly, it helps anti free zone argument. Nobody in that club had anyway to defend because obviously clubs like that are GUN FREE.
You want to put guns in the hands of people who are largely intoxicated/high and agitated by all the kinds of drama that happens in nightclubs? Wow.