Maybe the family were sleeper agents? Dad pretended to be a libertarian, bought multiple weapons over the years and emeshed himself in the gun culture. When the son was 10, fake libertarian Dad bought an AR style rifle for his son to use 10 yrs later to try and assasinate the GOP figurehead who just happened to be a former POTUS, but wasn't even in politics at the time the weapon of destiny was purchased...
The subtrefuge continued, as the family pretended to join the MAGA movement, placed MAGA regalia/ pro-Trump signs in their yard, which they made sure neighbors noticed. The assasin in training became known among his classmates as someone known for always taking the right wing opinion in debates/class discussions, and was made fun of/isolated by peers for wearing hunter and military camoflage to school and just being kind of different...But it was always a secret identity and all the while he was being groomed by the FBI/SS (known bastions of liberalism) to try and assasinate Trump.
So why did they wait till 2024? The Butler PA area is heavy Trump country, having voted for him in both 2016 and 2020. He's spent a lot of time at rallies in that area over the years, so why not have the kid shoot him on one of those trips? Including in 2020 when he was running for re-election?
They had the kid register as a Pub in 2021, the same month he turned 18 and could legally do so. How exactly did they manipulate Trump into scheduling a rally 50 miles from the kid so they could put their dastardly plan into operation on that particular Sat? And why choose an area like Butler, where the local officials and law enforcement were likely to be overwhelmingly pro-Trump? Wouldn't that make their job so much more difficult?