I think TM's suggested per curiam is a proper way of handling this mess. There is one error, however. Seven lines from the bottom, the phrase "which is joined" should read "which are joined" since it is the referenced Parts, rather than TM's opinion, which have been joined by the listed Justices. I assume both TM and LP are making the necessary changes in their own opinions .
Madans, A.S. Clerk Memo, Arizona Governing Comm. V. Norris, 463 U.S. 1073 (1983). Box 367, Harry A. Blackmun Papers, Manuscript Division, Library of Congress, Washington, D.C.