Would have to change this law:
28 U.S. Code § 1
The Supreme Court of the United States shall consist of a Chief Justice of the United States and eight associate justices, any six of whom shall constitute a quorum.
(June 25, 1948, ch. 646, 62 Stat. 869.)
https://www.law.cornell.edu/uscode/text/28/1?msclkid=9636f9ecb85511eca7148afe60f4bd71
My question isn't about packing the court. My question is about pre-approving nominees for future openings.