But he wasn’t just searching for big events with lots of people, or shooting randomly into a crowd of people. His research apparently focused on things like the Kennedy assassination, not the mass shooter who murdered all those concertgoers in Vegas.
All evidence released so far suggests he wanted to kill one of the two major party candidates and didn’t particularly care which one. This is consistent with a 1997 Secret Service study which found that most assassins and would-be assassins of public figures rarely have political motives.
If we narrow the definition of “assassin” to someone who is a rational person with a clearly articulated political ideology then most people who have shot American Presidents probably wouldn’t be classified as such.