I keep telling people in Seattle: this is a national crisis, we're not the exception, and no one is talking about it at the Federal level. Least of all President Sociopath.
It is not a Federal problem, other than any 1960s-1970s Federal laws there might be that increase the difficulty of the involuntary commitment process (I think this is a largely state law problem).
States have made involuntary commitment of the insane extremely difficult.
States and cities have been refraining from enforcing drug laws, or simply legalizing/decriminalizing selected drugs.
States have made themselves social program magnets.
Cities have chosen not to enforce - or repealed - their vagrancy laws.
Cities have chosen to enable homelessness by encouraging or operating homeless shelters.
Cities have chosen to enable addictive drug use through needle "exchange" programs that are actually free needle programs.
States and cities have chosen to increase the scarcity - and therefore the cost - of housing through anti-growth and enviro laws and through screw-the-developers regulations and fees and overlapping permit processes.
States and cities have chosen to dumb down school academics and waste classroom time through mandated activist-driven social-programming subjects.
Bums and alkies have probably been around the US since 1776, and the drug-dependent probably since the 1860s, if not earlier. Homelessness, to use the current euphemism, predates Donald Trump's birth by centuries. States and cities used to discourage it, but have been encouraging it and enabling it since the Dems decided in the 1980s - against Reagan - to exploit the sacred homeless for political gain.