There’s a reason every POTUS has a Secret Service detail. So yeah, it’s been imagined. Presidents have been shot and killed before, and Trump himself was shot during the lead up to the most recent election.
Again, the Secret Service is there to protect against all threats and the US Military there for every single other threat above the Secret Service’s pay grade and scale.
It’s the most dangerous and most protected job in America no matter what the POTUS is actively doing at any and every single moment.
I think y’all are so quick to try and criticize everything around the President that you’re kinda missing my point:
Of course there are people that would love to target the POTUS. The Secret Service detail exists for a reason. That reason being that yeah, it’s an unsafe job, and having them there is how we prevent a foreign adversary from just walking right into the White House and doing what we did to Maduro.