The supreme court has appellate jurisdiction over all courts and may hear original actions and proceedings. The supreme court may issue all writs necessary in aid of its jurisdiction.Item: On August 20, the Wisconsin Supreme Court granted the State Government Accountability Board a week's extension in filing its response to the complaint lodged in this action. The GAB's response is now due on August 27. On August 13, the court had ordered an injunction against the GAB preventing it from enforcing an election law rule even though the court has not yet taken jurisdiction of the case, nor will the court decide to do so until at least September 13.
— Wis. Const. art. VII, § 3.
Of some further interest to an arcane but important topic:
[C]ongressional enactment of sections 13 and 14 of the Judiciary Act of 1789, as well as early Supreme Court interpretation of these provisions, strongly suggests that Congress intended the power to issue writs to be "derivative" of jurisdiction previously established.[fn]157. . . .— Lonny Sheinkopf Hoffman, Removal Jurisdiction and the All Writs Act, 148 U. Penn. L. Rev. 401, 436-37 (citations omitted).
[fn]157 It also has been argued by Professor Akhil Reed Amar, based on the language of the Judiciary Act of 1789, that section 14 was not intended to be a source of original jurisdiction. Professor Amar points out that sections 14, 15, and 17 of the First Judiciary Act reveal a distinction between the word "power" and "jurisdiction." Thus, in section 14, federal courts have the "power" to issue writs which may be necessary for the exercise of their respective "jurisdictions." Parsing the Act’s text in this manner, Professor Amar concludes "it is clear from context that the Act is investing courts with certain authority if and when they have independently founded jurisdiction. . . . 'Jurisdiction' must be established first, and independently; 'power' then follows, derivatively."
Much as I was suggesting.
Federal removal jurisdiction — whereby federal courts might assume jurisdiction over cases initiated in State courts — is a separate matter again, obviously, but I have always understood conservative judges to claim as a central component of their adjudicative methods the tracing of constitutional language to "original intent" and common law origins. At least, that's their election campaign promise.
Justice Prosser (together with Gableman) undertook to explain that a majority of the court had found a type of jurisdiction not enumerated in the Wisconsin constitution — subject matter jurisdiction — but they didn't argue the point very convincingly. I wonder whether the Government Accountability Board will raise the issue. It should.