An Arizona state constitutional amendment, passed by the voters, may be struck down by SCOTUS because it (quite intentionally) cuts the legislature out of the role of establishing congressional districts. The US Constitution says that the "time, place, and manner" of state elections shall be determined by the state's legislature, and a majority of the justices, based on their questions in oral arguments today, didn't seem to think that the amendment seemed to comply with that.
I have my doubts, to be honest, largely because I think not letting legislators legislate their own district boundaries seems like an extraordinarily good idea to remove the conflict of interest that results in grotesque gerrymandering. (Both parties have been and are guilty of it, but the most egregious examples at the moment are from the GOP after their 2010 victories in statehouses.) To me, the point is not that the commission in Arizona itself is not a "legislature," but that the commission was set up by the voter of the state, following the state's own constitution as to how laws and amendments may be passed — serving themselves as a legislature.
It's also not completely convincing to me that "time, place, and manner" of elections necessarily includes how districts are drawn. Nor that, in fact, the state legislature has standing in being "harmed" by the amendment. (I can imagine individual representatives, no longer in a "safe" district, considering themselves harmed, but it would take pretty big balls to be that bluntly political about it, arguing that the US Constitution ensures the ability of a legislator to keep his reelections easy.)
We will, I suppose, see. The current SCOTUS has not been much of a friend to anything that smacks of electoral reform, and doesn't seem to consider gerrymandering much of a problem.
(h/t +Andreas Schou)
Supreme Court Justices Skeptical Of Non-Legislative Redistricting
The Supreme Court seems likely to strike down state laws that take redistricting completely out of the hands of state legislatures.
Another hen for the fox.