Jack Balkin: jackbalkin at yahoo.com
Bruce Ackerman bruce.ackerman at yale.edu
Ian Ayres ian.ayres at yale.edu
Mary Dudziak mary.l.dudziak at emory.edu
Joey Fishkin joey.fishkin at gmail.com
Heather Gerken heather.gerken at yale.edu
Abbe Gluck abbe.gluck at yale.edu
Mark Graber mgraber at law.umaryland.edu
Stephen Griffin sgriffin at tulane.edu
Bernard Harcourt harcourt at uchicago.edu
Scott Horton shorto at law.columbia.edu
Andrew Koppelman akoppelman at law.northwestern.edu
Marty Lederman msl46 at law.georgetown.edu
Sanford Levinson slevinson at law.utexas.edu
David Luban david.luban at gmail.com
Gerard Magliocca gmaglioc at iupui.edu
Jason Mazzone mazzonej at illinois.edu
Linda McClain lmcclain at bu.edu
John Mikhail mikhail at law.georgetown.edu
Frank Pasquale pasquale.frank at gmail.com
Nate Persily npersily at gmail.com
Michael Stokes Paulsen michaelstokespaulsen at gmail.com
Deborah Pearlstein dpearlst at princeton.edu
Rick Pildes rick.pildes at nyu.edu
Richard Primus raprimus at umich.edu
K. Sabeel Rahmansabeel.rahman at brooklaw.edu
Alice Ristroph alice.ristroph at shu.edu
Neil Siegel siegel at law.duke.edu
Brian Tamanaha btamanaha at wulaw.wustl.edu
Mark Tushnet mtushnet at law.harvard.edu
Adam Winkler winkler at ucla.edu
The transcript of the McDonald v. City of Chicago oral argument is here. The Court seems likely to apply the Second Amendment to the states but will likely use the Due Process Clause rather than the Privileges or Immunities Clause. Not a single Justice who spoke seemed inclined to use the Privileges or Immunities Clause, although, as usual, Justice Thomas, the Justice most likely to find the argument hospitable, was silent.
The Court did not spend much time worrying about the historical record, nor did the lawyers have much time to discuss it. Instead, individual Justices like Justice Kennedy and Justice Ginsburg wondered whether using the Privileges or Immunities Clause would require incorporation of the grand jury right and the right to civil trials, which presumably, was a deal breaker for them.
Amusingly, some of the Justices were worried that using Privileges or Immunities would open up the possibility of implied fundamental rights, which they already recognize under the Due Process Clause. Justice Scalia in particular remarked that he had essentially accepted substantive due process. Up to a point, that is: he bitterly resists every new implied fundamental right and still would like to overrule some cases recognizing such rights. As Doug Kendall notes below, it seems easier to take a very limited view of implied fundamental rights when one is working with the Due Process Clause than with the Privileges or Immunities Clause, whose text was designed to recognize such rights. The ghosts of Lochner and Roe v. Wade hovered over the argument. "Seems" is the operative word in the previous sentence, however. In fact, as I note below, using the Due Process Clause instead of the Privileges or Immunities Clause hasn't really stopped the courts from finding implied fundamental rights.
The Justices as a group seemed to think that not much is gained by moving to Privileges or Immunities when there is already a jurisprudence under the Due Process Clause. The differences in language in the two texts, and their relative compatability with implied fundamental rights, didn't seem to matter much to them. The history of the two clauses seemed not to matter much at all. This should not be surprising. As a rule, the Justices only invoke history when it is consistent with views they already hold.
Justice Stevens channeled Justice Frankfurter, arguing that perhaps incorporation to the states did not incorporate the whole right, but just its core elements. Justice Breyer argued that the Second Amendment was special because it involved a threat to life, and therefore should not be incorporated or should only be partly incorporated against the states. The Court has previously rejected Justice Frankfurter's theory, but as a result of a fractured court in Apodaca v. Oregon, it has incorporated only part of the sixth amendment jury trial right.
Nevertheless, it is unlikely that there are five votes for partial incorporation. Rather, there are probably five votes for full incorporation under the Due Process Clause.
The bottom line of the oral argument, not surprisingly, is that (excepting Justice Kennedy and possibly Justice Thomas) the Justices' substantive views on gun rights and abortion rights will determine the outcome of this case:
Many of the Justices who support incorporation of the Second Amendment don't want to open the door to new implied fundamental rights, which they fear might be easier to protect under the Privileges or Immunities Clause. Thus they support incorporation of the Second Amendment under the Due Process Clause (ironically) because they fear more cases like Roe v. Wade and Lawrence v. Texas, which were decided under the Due Process Clause. If they retain existing doctrine, they believe that (somehow) it will be easier to refuse to recognize new implied fundamental rights under the Due Process Clause.
Conversely, the Justices who support implied fundamental rights don't like using the Privileges or Immunities Clause because they oppose incorporation of the Second Amendment period, and continue to think Heller was wrongly decided. Therefore they prefer arguing that the Amendment shouldn't be incorporated under any clause. Because not all of the Bill of Rights has been incorporated under the Due Process Clause, and all of it would be incorporated if one used the Privileges or Immunities Clause, they prefer the Due Process Clause. Moreover, if one is to incorporate the right, it should be incorporated under the Due Process Clause because there is one precedent (Apodaca) which suggests that one can incorporate rights under the Due Process Clause only partially.
I should add, finally, that the hope of some of the Justices that continuing to stick with the Due Process Clause to hold off recognition of new implied fundamental rights is a fool's errand: History shows that if you close down one avenue for implied fundamental rights (privileges or immunities) another avenue opens up (due process). That is because, whether you like it or not, there has been powerful public pressure for the recognition of implied fundamental rights throughout American history, and this, not surprisingly, is one reason why the Constitution contains both the Ninth Amendment and the Privileges or Immunities Clause.