I explained in a recent post on the census citizenship question case the following:

The Supreme Court is already hearing a case about one aspect of Judge Furman’s decisions: whether the judge improperly allowed some discovery into the mindset of Secretary Ross and AAAG John Gore. That question seems mostly moot: Judge Furman relied only on material in the public record in reaching his decisions, so a remand would simply lead to the same decision. (It may not betechnically moot.)

But given the press of time, I expect DOJ will seek a stay of Judge Furman’s ruling, perhaps by going directly to the Supreme Court and seeking to bypass the 2nd Circuit. DOJ might even seek cert. directly rather than going through the 2d Circuit, and the Supreme Court might even treat a stay request as a cert. petition and grant it.

Well now we have the mootness argument in the already existing Supreme Court case. You can find the motion to dismiss at this link. A snippet:

First, Petitioners’ chief concern—that “Secretary Ross will be forced to prepare for and attend a deposition, which cannot be undone,” Pet. Br. 44— has been rendered moot, because the district court vacated the decision that is the subject of the mandamus petition. New York, slip op. 277. This Court’s interlocutory review of the district court’s order authorizing the Secretary’s deposition is thus not only unnecessary but also outside the scope of the Court’s jurisdiction.

Second, the final judgment does not turn on “evidence of the Secretary’s mental processes.” Pet. Br. 44. Rather, the district court reached its decisions as to the APA “based exclusively on the materials in the official ‘Administrative Record,’” New York, slip op. 8, concluding that extra-record evidence merely buttressed its extensive findings and conclusions of law, e.g., id. at 97, 99, 231 n.68, 241 n.74. Any remaining disputes between the parties over the propriety of discovery outside of the administrative record can and should be addressed through review of the final judgment.

You can find the plaintiffs’ brief on the merits in the SCOTUS case at this link.