[ColoradoTree]

On the topic of a recess appointment, that would only work if the Senate were ever formally in recess, which I don't expect Mitch McConnell to allow now that there is a Supreme Court vacancy. 

Here, the distinction between what we understand to be a recess--nobody is there, they're all back in their home states--and what the Senate itself considers a recess is what matters.  That's because of the Senate practice of holding "pro forma" sessions where one Senator gavels the Senate into session and gavels it closed again a minute or so later, despite the presiding Senator being the only one in the chamber (or even in Washington).  Historically, they were used to make sure both the Senate and House were complying with Article I, Section 5 of the Constitution, which forbids one house from adjourning for more than three days without the consent of the other house.  (This consent is easy to get when the House and Senate are of the same party, but more difficult when there is divided government, and particularly when the House is of a different party than the President.)  Whatever the original purpose, the effect of those sessions is to keep the Senate technically in session so that there is no formal recess that would trigger the President's ability to make a recess appointment, and their use has evolved to make this one of the main reasons for holding pro forma sessions.

This practice was challenged recently in the Noel Canning v. NLRB case.  Quick background: The National Labor Relations Board lacked a quorum to conduct business from 2007 through 2013, effectively making labor disputes incapable of resolution until a quorum was restored.  President Obama had trouble getting nominees through the Senate (even when Democrats held the majority, Republicans threatened a filibuster), so made a trio of recess appointments on January 4, 2012 to restore the Board to a quorum.  The issue was that the Senate had not technically been in recess, because they had one Senator stay behind to gavel a session open and close it a minute later (though, ironically, it was a Dem-controlled Senate doing it here, obviously not to stymie a President of their own party, but to comply with Art. I, Sec. 5, because the Republican-controlled House wouldn't agree to a recess).  The Supreme Court ultimately ruled that the Senate is in session when the Senate says it is, so pro forma sessions effectively foreclose the ability to make recess appointments.

Thus, while the recess appointments power still exists, it is severely limited by current Senate practice.  For it to apply, you'd need a Senate majority of the same party as the President, but in the 51-59 seat range.  More than that and you could just end the filibuster of the nomination and confirm the nominee.  You'd also need a House majority to concur in the recess to allow the Senate to be formally in recess (and for that recess to last longer than ten days, per the Noel Canning case).  So, assuming that McConnell has someone mind the store until the new Congress is sworn in, the recess appointment power is not an option for confirming a successor to Justice Scalia. 

[ColoradoTree]

On the topic of a recess appointment, that would only work if the Senate were ever formally in recess, which I don't expect Mitch McConnell to allow now that there is a Supreme Court vacancy. 

Here, the distinction between what we understand to be a recess--nobody is there, they're all back in their home states--and what the Senate itself considers a recess is what matters.  That's because of the Senate practice of holding "pro forma" sessions where one Senator gavels the Senate into session and gavels it closed again a minute or so later, despite the presiding Senator being the only one in the chamber (or even in Washington).  Historically, they were used to make sure both the Senate and House were complying with Article I, Section 5 of the Constitution, which forbids one house from adjourning for more than three days without the consent of the other house.  (This consent is easy to get when the House and Senate are of the same party, but more difficult when there is divided government, and particularly when the House is of a different party than the President.)  Whatever the original purpose, the effect of those sessions is to keep the Senate technically in session so that there is no formal recess that would trigger the President's ability to make a recess appointment, and their use has evolved to make this one of the main reasons for holding pro forma sessions.

This practice was challenged recently in the Noel Canning v. NLRB case.  Quick background: The National Labor Relations Board lacked a quorum to conduct business from 2007 through 2013, effectively making labor disputes incapable of resolution until a quorum was restored.  President Obama had trouble getting nominees through the Senate (even when Democrats held the majority, Republicans threatened a filibuster), so made a trio of recess appointments on January 4, 2012 to restore the Board to a quorum.  The issue was that the Senate had not technically been in recess, because they had one Senator stay behind to gavel a session open and close it a minute later (though, ironically, it was a Dem-controlled Senate doing it here, obviously not to stymie a President of their own party, but to comply with Art. I, Sec. 5, because the Republican-controlled House wouldn't agree to a recess).  The Supreme Court ultimately ruled that the Senate is in session when the Senate says it is, so pro forma sessions effectively foreclose the ability to make recess appointments.

Thus, while the recess appointments power still exists, it is severely limited by current Senate practice.  For it to apply, you'd need a Senate majority of the same party as the President, but in the 51-59 seat range.  More than that and you could just end the filibuster of the nomination and confirm the nominee.  You'd also need a House majority to concur in the recess to allow the Senate to be formally in recess (and for that recess to last longer than ten days, per the Noel Canning case).  So, assuming that McConnell has someone mind the store until the new Congress is sworn in, the recess appointment power is not an option for confirming a successor to Justice Scalia.