Against growing odds, Gov. Jerry Brown formally asked the U.S. Supreme Court late Friday to intervene once again in California's yearslong battle with federal judges over control of the state's prison system.
The Democratic governor filed his formal appeal asking the justices to overturn a lower court decision requiring the state to reduce its prison population by nearly 10,000 inmates by the end of the year to improve conditions.
By "formal appeal" he presumably means the jurisdictional statement. The notice of appeal was filed in the district court some time ago. The docket for this case is not yet online at the Supreme Court, so I can't check it there yet.
For the small subset of cases that can be appealed directly to the Supreme Court, the procedure is to file a "jurisdictional statement" rather than a certiorari petition. Since the Court has no choice but to take the case if they have jurisdiction, in theory, the purpose of this document is nominally just to convince them they have jurisdiction.
In reality, though, the appellant must convince the Supreme Court to accept full briefing and argument rather than affirm summarily. For this reason, the jurisdictional statement is more like a certiorari petition in practice that it would appear to be on the face of the rules.