Don't misconstrue rational for deliberate. Rational people don't shoot themselves in protest. Throwing dandelion seeds all over his golf courses would get Trump's attention and thus everyone else's attention far more than shooting oneself.
As much as those attributing it to "TDS". However, as a student of human behavior in general, it has been my observation that people who deliberately self-harm, at the very least, tend have emotional problems. I'm not including people already dying of terminal illnesses. This man is 68-years-old. It could also be a symptom of the onset of some form of dementia.