It depends on where you draw the line for “attempt” - the Secret Service isn’t an exactly candid organization (to put it lightly) and the media/public doesn’t spend much time focusing on the foiled plots they do learn about (insert your opinion as to the “why?” here). My own assumption is that the threat vectors against those that are granted Secret Service protection are probably numerous and coming from many different directions.
It depends on where you draw the line for “attempt” - the Secret Service isn’t an exactly candid organization (to put it lightly) and the media/public doesn’t spend much time focusing on the foiled plots they do learn about (insert your opinion as to the “why?” here). My own assumption is that the threat vectors against those that are granted Secret Service protection are probably numerous and coming from many different directions.