Will States Challenge the “Nebraska Compromise”?

The AP reports several state attorneys general are looking into potential legal challenges to the health care bill (assuming it passes).

The top prosecutors in seven states are probing the constitutionality of a political deal that cut a funding break for Nebraska in order to pass a federal health care reform bill, South Carolina’s attorney general said Tuesday.Attorney General Henry McMaster said he and his counterparts in Alabama, Colorado, Michigan, North Dakota, Texas and Washington state – all Republicans – are jointly taking a look at the deal they’ve dubbed the “Nebraska compromise.”

“The Nebraska compromise, which permanently exempts Nebraska from paying Medicaid costs that Texas and all other 49 states must pay, may violate the United States Constitution – as well as other provisions of federal law,” Texas Attorney General Greg Abbott said.

I am quite sympathetic to the idea that special treatment of one state, or broader differential treatment of different states, for tax or regulatory purposes is problematic.  Such measures are significantly more so than traditional pork-barrel appropriations.  Federal laws should be laws of general application.  Yet I am unsure of the basis upon which such things could be challenged as unconstitutional, and the AP story linked above is sketchy on the details of what the various state AGs are planning.