They did take the case brought by the State of Texas challenging Obama's immigration amnesty. They did not need to take a second case on the same issue, especially because Arpaio's standing was questionable (it was not the State of Arizona or Maricopa County that sued, only one elected official) and Texas's standing was clearer.
SCOTUS.
Thank you for explaining that. I hope we can trust Roberts on this issue. I figure even he has to know by now that everyone knows why he backstabbed conservative issues.