Bush’s approval rating benefited from the US being attacked, and then responding. Trump has the order wrong; preemptively attacking countries (even bad ones) doesn’t poll very well with Americans.
(This is ahead of Trump’s base being isolationist; it’s not even clear who wants this besides conventional hawks.)
Combined with the fact that the media will be confused about how to respond. You’ll have Iranian diaspora celebrating, like Venezuelans did after the capture of Maduro, making it impossible for the media to frame this simply in terms of “Trump is racist.” As a result, the whole thing will get memory holed, just like the Venezuela attack.
I didn’t say the attack on Iran was like 9/11. I was responding to OP’s hypothetical about what would happen if the situation was reversed and Trump was killed.
(This is ahead of Trump’s base being isolationist; it’s not even clear who wants this besides conventional hawks.)