Earlier quoted context omitted.
There has to be a line draw somewhere. Generally people who say this don't actually have regular interactions with aggressive, hostile, homeless. Or are you just really cool with going to a coffee shop and have someone screaming in a pile of their own feces 20 or so feet away?
The problem is that once you draw "the line", then what? Warehouse a bunch of helpless people in overcrowded prisons? Bus them to some other less-draconian municipality? Forcibly drug them into quasi-submission and then turn them loose again until the depot injection wears off? Or perhaps we should "just kill 'em", as Fox & Friends cohost Brian Kilmeade once suggested?
If they are mentally ill and unable to care for themselves or pose a threat to the community because of their mental illness, they should be institutionalized and treated. If they are able to be released into the community after a period of time, checks should be performed to ensure compliance with treatment/medication.