There is much to be said in favor of a supermajority rule for confirming Supreme Court Justices. As Mike Rappaport and I argue in the Judicial Filibuster, the Median Senator and the Countermajoritarian Difficulty, the result of such a rule will be more moderate justices, less likely to go to any extremes. At a more theoretical level, a supermajority rule will temper the countermajoritarian difficulty — the problem created by an unelected judiciary invalidating the decisions of the popularly elected branches. Judicial review under this confirmation rule would be more likely to impose the long-term limitations on popular government that most people themselves desire.
The filibuster, however, is a weak supermajority rule, because a partisan majority of Senators can change it any time through the so-called nuclear option. Despite my preference for a supermajority confirmation rule, the filibuster is unlikely to survive, if Senator Chuck Schumer has implied, the Democrats are inclined to filibuster Trump’s Supreme Court nominees. Noah Feldman is thus wrong in claiming that it is plausible that the Supreme Court will continue to operate with only eight members.
First, the filibuster for Supreme Court confirmations has been gravely weakened by the previous Democratic controlled Senate’s elimination of the filibuster for other nominations, both for the executive branch and for the lower federal courts.