Article II of the US constitution: "...and he[the President] shall nominate, and by and with the advice and consent of the Senate, shall appoint ambassadors, other public ministers and consuls, judges of the Supreme Court, ...
That is all the constitution says about appointing Supreme Court judges. There is nothing relating to timing of the nomination/confirmation. Any change to this article would require a constitutional amendment, i. e., ratification by 2/3 vote of house of reps and senate and ratification by 3/4 of states. Not bloody likely given current attitudes of the various parties.
However, congress has the constitutional authority to establish the number of judges on the SC, and has done so in the past. I think the Democrats need to be very cautious about making any such radical changes, such as packing the court with 15 judges, if they should win the presidency and congress. Long term consequences are always surprising and usually undesirable. But it might be an effective threat (which may backfire!).
™ Version 4.2
