Could the Supreme Court rule against court packing?

[True Federalist (진정한 연방 주의자)]

There's plenty of precedent for changing the size of the Court via legislation. About the only way I could see SCOTUS making a ruling would be if a hypothetical Judiciary Reform Act affected the tenure of existing justices in some manner. For example, a bill that tried to shrink the Court immediately to 7 by removing the 2 junior most justices would get struck down unanimously.

[True Federalist (진정한 연방 주의자)]

There's plenty of precedent for changing the size of the Court via legislation. About the only way I could see SCOTUS making a ruling would be if a hypothetical Judiciary Reform Act affected the tenure of existing justices in some manner. For example, a bill that tried to shrink the Court immediately to 7 by removing the 2 junior most justices would get struck down unanimously.

The hardball play here would be to remove the two junior-most justices, “bow to public pressure” and expand the court back to nine, but add two new Biden justices rather than re-adding Kavanaugh and Barrett.

Which would be definitely unconstitutional and also unprecedented.

[True Federalist (진정한 연방 주의자)]

What if Congress passes something akin to Buttigieg's plan, which establishes that at least some of the new justices must be unanimously approved by the sitting justices? Can they strike that down on the grounds that it interferes too much with the independence of the Court by compelling justices to confirm new ones?

First off, any attempt to retroactively apply such a rule would clearly be unconstitutional.

But if struck down in total, it wouldn't be because of interference in Court independence, it would be because it would be an unconstitutional delegation of power to the Court, much as how in Marbury, the Court found it was unconstitutional to give the Court the power to issue writs of mandamus.