WASHINGTON -- An eight-member Supreme Court appeared skeptical on Monday that President Barack Obama s decision to defer deportation for millions of undocumented immigrants could be subject to a multi-state legal challenge in a court of law.

At issue in the 90-minute hearing in United States v. Texas -- perhaps the most deeply political and consequential case the justices will decide this year -- are the presidents executive actions on immigration, which have been on hold for more than a year as a result of a conservative challenge from Texas and 25 other states.

If Texas and the other states are allowed to sue, then every case of political disagreement where states disagree [with the federal government] would come before the court, said Justice Stephen Breyer.

At the heart of the case are two constitutional questions: Whether the states have legal standing to sue over how the federal government administers immigration policy, and whether the policy itself complies with the mandate that the president take care that the laws be faithfully executed.

On this latter point, centrist Justice Anthony Kennedy, who in 2012 largely sided with the federal government in another immigration case, seemed to share the concern of the conservatives states that sued to invalidate the presidents programs.

"It's as if the president is setting the policy and the Congress is executing it," Kennedy said. "That's just upside-down.