The real answer is, it’s complicated. Involuntary commitment (and related acts) is a pretty extreme measure for when an individual is a danger to themselves or others. There’s no evidence that he’s trying to hurt himself, and the “other” usually has to be a specific person, not just a hypothetical class of others to have standing.

And it’s even more complicated by the idea that the president has been gifted broad immunity regarding anything remotely tangential to official powers. So you can’t even say you, specifically, are in danger due to things done by the government, so long as there is some whack job theory under which it’s being executed.

If he came alone to your house naked and covered in nacho cheese with a knife threatening to hurt you, you’d probably have a case. Depending on the state, it probably takes something similar even for a family member or acquaintance (but check your local laws).