Can Portland sue the federal government for causing the homeless crisis? Few would argue that the homeless epidemic can, more or less, be traced back to trickle-down Reaganomics—why should we shoulder the burden of their bad policies? — Garrick A.
Ah, that redoubtable legal standard, "more or less." Judges can't get enough of it! There's nothing a court of law enjoys more, when painstakingly reconstructing a series of causal links, than a brisk round of good old-fashioned hand-waving, perhaps punctuated by an impish shrug.
(Don't even get me started on "few would argue," except to suggest that the reason so few are arguing may have less to do with the irrefutability of your position than with the fact that you're standing on a street corner with a colander on your head.)
Sorry to draw out my answer to your question, Garrick; it's just that it doesn't take very long to say "no." (I tried saying "nope" instead, but it's not much better.) Perhaps I should put it this way: I've got bad news, I've got good news, and then I've got more bad news.
First, the bad news: Under a legal principle called "sovereign immunity," the government cannot be sued by its citizens. This idea has its roots in English common law, under which it was illegal to sue the king. (One justification for this was that courts derive their authority from the government, so they can't compel the source of their own power. Another was, "I'm the king, so fuck you.")
Now, the good news: Drilling down, we find that the longer version of this rule is, "You can't sue the government, unless the government gives you permission." Luckily, it has given us that permission, in the form of the 1946 Federal Tort Claims Act.
Finally, the bad news: The FTCA is only a limited waiver of sovereign immunity. You can sue for the standard types of negligence Americans love to sue for (slipping on a banana peel at the Social Security office, getting rear-ended by a postal truck), but not for broad policy decisions (starting wars, colluding with the Illuminati). Disappointing, but probably just as well.