Dr. Norm Matloff writes to his mailing list:
In all my years as a researcher, I've never heard of anything like it.
A bevy of prestigious academics with varied viewpoints is gathered to share insights on an important national topic--so far so good. Unfortunately, this part of the conference is closed to the public--not so good, but not unusual either. BUT...following this closed-doors part of the conference, there is a very public session, televised on C-SPAN and available on the Web. And the speakers in this public session, largely contradict what many of the speakers in that private session had said, without disclosing that they do view things differently. AND...the speakers in the public session all have very strong vested interests in the topic at hand.
A passage in the [linked]report by science journalist Beryl Benderly sums it up:
This elite and visible unanimity, however, belied the tangle of issues revealed earlier in the day during the smaller, nontelevised meeting where scholars  from economics, political science, law, and public policy examined the likely difficulties of devising immigration policies that help the economy without harming immigrants or people who are already in the country. Daytime speakers also considered the difficult job market  facing many STEM workers, another issue that the three evening panelists’ statements ignored.[The Job Market | Bordering on Confusio n By Beryl Lieff Benderly, ScienceMag, January 04, 2013]
Sidebar quote from Benderly article:
“When the companies say they can't hire anyone, they mean that they can't hire anyone at the wage they want to pay.” —Jennifer Hunt