Not any different than a Tom Clancy novel.
Or many other novels, Plots against a President are the stuff of movies.
I don't think know that the post belongs here though there have been many more offensive posts who have survived.
The quote is from the guy who assassinated Garfield.
It is a catchy line attached to an ad for a sniper rifle. And not even the best sniper rifle around, though it has the advantage of being man-portable and requiring minimal setup.
However if one were going to after a heavily protected high-value target from a non-combat, static position there are many other sniper rifles which would be better. I understand there are laser affairs which even calculate windage. That's sophisticated, and makes every hostage situation very iffy for the badguy.
Arf