Three Justices dissent from denial of cert in Illinois lawsuit over solitary confinement of mentally ill inmate

As mentioned in this prior post, this morning's new Supreme Court order list included a cert grant in a federal drug case and a lengthy dissent from the denial of cert in a state prison conditions case.  The cert grant in Diaz v. US could touch on a variety of interesting issues that might provide to divided the Justices in ways other than the now "usual" 6-3 divide.  But the state prison conditions case, Johnson v. Prentice, did produce the usual 6-3 split, with Justice Jackson authoring a lengthy dissent joined by Justices Sotomayor and Kagan.  Here is how this dissent starts:

This Court has long held that the test for evaluating an Eighth Amendment challenge to a prisoner’s conditions of confinement involves determining whether prison officials acted with “deliberate indifference” to a substantial risk to an inmate’s health or safety.  Estelle v. Gamble, 429 U. S. 97, 104 (1976).  With respect to the Eighth Amendment claim at issue in this case, the Court of Appeals for the Seventh Circuit affirmed the grant of summary judgment to prison officials without applying that well-established standard. Given this indisputable legal error, I would grant certiorari and summarily reverse.

According to the dissent, the case involved an "unusually severe" example of solitary confinement for Johnson.  But I am not too surprised from reading the dissent if this may have seemed to other Justices like an error-correction case, especially with the dissent suggesting the case only concerned whether there was "a genuine issue of material fact for the jury, under the facts and circumstances presented here, such that summary judgment was not appropriate."  I certainly would like to see the full Court take up some of the issues surrounding "severe" use of solitary confinement, but I am not sure this Johnson case would have been ideal for addressing important broader issues.