Presidential assassin Cole Tomas Allen. What was his motive?

At last nights white house correspondents' dinner Cole Tomas Allen - a California teacher of the month and registered democrat - tried to breach the metal detectors "matrix style" while openly toting a shotgun, at least one pistol, and multiple knives.

He shot one officer before being taken into custody alive. Let's speculate on Mr. Allen's motives in this thread.

It would seem obvious that only a mentally impaired person could believe this assassination plan would succeed. But that does not answer the question of why. Possibilities include:

1. Extremists immediately claimed this was a staged/fake assassination. But this seems unlikely, since the shooter is alive, unhurt and talking.

2. Mr. Allen was duped into the attack by some domestic or foreign organization which encouraged him and provided logistical advice, and assumed he would be killed in hail of secret service gunfire. This cannot be ruled out. Mental cases like Lee Harvey Oswald turn up frequently in these scenarios

3. My own theory: Mr Allen could turn out to be some sort of antisemite or pro-Palestine enthusiast. If this is true there should be social media evidence.

What are your theories?