What penny did does not qualify as a the act of a vigilante. He was protecting himself and others from a madman on the subway, it was self defense. He was not out exacting revenge or taking the law into his own hands, he was simply tying to protect people from a lunatic the best way he knew how.
This move would be a positive message for the presidency and I would be especially impressed if he did so as his first act.
Vigilantism is not nice but it is a reactionary social ill. There are very few normal people who will waste their time policing safe streets.
Yet a citizen wanting to help another should gain a medal and not a sentence.
What penny did does not qualify as a the act of a vigilante. He was protecting himself and others from a madman on the subway, it was self defense. He was not out exacting revenge or taking the law into his own hands, he was simply tying to protect people from a lunatic the best way he knew how.
He was doing the job the NYPD used to do.
You have highlighted a very important difference.