AUSTIN, Texas — Four more states have joined a Texas-led coalition suing the Obama administration over executive action on immigration.

The addition of Arkansas, Michigan, North Dakota and Oklahoma brings to 24 the number of states fighting the order in a federal district court in Brownsville.

Announced last month, the president's unilateral move is designed to spare millions of people living illegally in the United States from deportation. But the lawsuit accuses the White House of "trampling" the U.S. Constitution.

Outgoing Attorney General Greg Abbott says Texas is uniquely qualified to sue because its sprawling border with Mexico means it will be especially harmed.

Abbott, the governor-elect of Texas, added Wednesday that the presidential decree "circumvents the will of the American people."