That's an incredible story, especially from a Europe where immigration controls is on everyone's lips.
Informally, I recall learning that the 'solution' for inhuman insane asylums was to just release everyone and close them down. That's quite probably where a good portion of the 'homeless' problem comes from; there are of course also untreated veterans and just pure scam-artist pan-handlers.
The actual solution is also a difficult and politically impalpable issue:
* national healthcare including drug addition treatment and mental health
* an unending 'new deal'
* + everyone trained to aptitude
* + non-broken-window fallacy job assurance
* adequate housing of actual quality near jobs
Also taxes / incentives (carrot+stick) at a federal level to pay for / encourage the correct behavior from all actors.http://hsh.sfgov.org/services/outreach-and-homelessness-prev...
But yeah I can see it being difficult to prove, and harder to action. If one state wanted to sue the other, what is the process? Congress? Supreme court?
Nebraska and Oklahoma vs Colorado was recently declined to be heard by the Supreme Court.
There's no immigration controls between the states because we're all part of the same country. Don't think it'd even be legal to try it, ever.
The only real "immigration controls" we have are for produce at the California border to control the immigration of insects, people are free to go wherever they want. Oh, and those annoying Border Control checkpoints not at the actual border to impede the movement of foreign nationals.
I agree that there's a problem to be solved but DC is far from squeaky clean...
Real numbers: https://www.washingtonpost.com/local/dc-has-the-highest-home...
Human waste, needles, garbage on the sidewalk is the result of hundreds of bad actors, which correspondingly takes significantly more resources to deal with. (And on that note, the state of Texas is the worst offender. Their official policy for dealing with their homeless during the Perry era, and still their unofficial policy, was to give their homeless showers and then a bus ticket to SF.)