Please, let's remember that the mentally ill aren't 'evil alien[s]', as the author describes her father. People considered mentally ill are those who generally have emotional and/or cognitive irregularities, be they subtle or strong. That still makes them human.
I recognize the need to expand involuntary commitment laws to include evidence of recent events beyond the past 15 minutes of an interview. I agree that something does need to be done about dangerous people in general, regardless of whether they are mentally ill or not. This is a problem that needs restrictive and supportive measures on many fronts.
However, most mentally ill people are not dangerous. The author's use of circumstantial stories, instead of statistical evidence strongly distorts the reader's understanding of a typically mentally ill person. In her story, almost every mentally ill person she mentions kills someone. But as the author says in the end, the mentally ill are statistically less likely to harm another than to be harmed by someone else.
I think that some of what the author hopes for is a good idea, but if people could be forcibly treated for mere delusions or minor symptoms, then that also includes the huge percentage of normal Americans who believe in or claim to have seen ghosts. Do unusual religious beliefs count as insanity? Are your political views ever considered 'irrational' by someone else? What happens to free thought and religion?
The problem with creating laws that chip away at civil liberties is that these laws can be abused or stretched to cover people who are in a 'grey area' and aren't a real danger. Those in power can take laws and apply them according to their personal preferences and values, at the expense of those who do little harm.
I think it's a good idea to have involuntary commitment laws only for the rare dangerous cases that exist. But in addition to that, human support is needed. Treating people well and showing gentle empathy will help win them over to the side of those who are trying to help. In the end, let's not harm the large majority who are closer to the middle of the grey area, and aren't dangerous.