Homelessness is a non accountable term used to avoid using the longer but more accurate "vagrants with substance addiction and/or mental illnesses".
Both Democrats and Republicans can be blamed equally for this quagmire, first because each group can and does politicize a problem when it shouldn't be and, second, because, at it's core, the issue is enshrined in this national bible we call the Constitution, something about freedom, which both sides like to invoke every time our elected government does something they are displeased with.
How difficult can it be for a city, county, state or federal government to forbid vagrants on city streets? Should be easy enough, right? Good luck. It's so easy to blame "The System".. individual responsibility, drug cartels, abysmal healthcare, greedy landlords, lack of morals, high this, low that... There's no resolve to end this because it's a master fuck project full of holes to be abused.
Having lived in a few countries, I see that other nations have grabbed the bull by the horns and addressed their "homelessness", mainly by plugging the holes one at a time over many decades, keeping what works and discarding what doesn't. Mental health support, substance abuse care, temporary housing, strict vagrant laws...Holes are patched enough to preserve society's good conscience; contributing a significant amount of tax monies to care for those who can't care for themselves. It's a heavy burden that America conveniently sweeps under the "freedom" label... Freedom to be a vagrant, a motto that both right and left can agree with from opposite sides of the political spectrum.
To be fair, we prefer to spend our tax money financing our military industrial complex and saving the world from itself, as we're told.