People always say NASA is underfunded, and it is, but we could end homelessness in America for the cost of funding NASA for 11 years. We could also pay for it over 10 or 20 years and it'd increase the federal budget by around half a percent or less. And that's at $400,000 per house which is probably a high estimate although there would be some overhead associated with locating housing in the right places and moving people around.
My point is that this is not an ambitious project. But then, who knows what happens if this eviction/foreclosure crisis is allowed to unfold.
Similarly the prison population I think is a static number but hundreds of thousands more probably flow through in any given year.