The court has asked to be briefed on a matter the administration must be reluctant to address; the Justice Department requested that the court not insert a “constitutional question” into the case. The question the court will consider is: Did Obama’s action violate the “ take care clause ”?

Obama has sworn to “preserve, protect and defend the Constitution,” which says the president shall “take care that the laws be faithfully executed.” Josh Blackman of the South Texas College of Law in Houston and adjunct scholar at the Cato Institute in Washington says that only three times has the court relied on the take care clause to limit executive actions, and the justices have never asked for a briefing on this clause.

In their brief, the states argue that “Congress has created a detailed, complex statutory scheme for determining” who qualifies for “lawful presence” in this country. No statute empowers the executive to grant this status to any illegal immigrant it chooses not to deport, let alone to confer “lawful presence” status on a class of many millions.

The states say presidents cannot “change an alien’s statutory immigration classification.” So, Obama is not merely exercising discretion in enforcing the Immigration and Nationality Act. He is altering this act so that previously prohibited conduct no longer violates the act.