Indiana is joining 16 other states in a lawsuit against President Obama's executive order on immigration.
President Obama issued the executive order last month, providing protection for parents of U.S. citizens from being deported. The order could affect up to 5 million undocumented immigrants.
In the wake of the president's decision, immigration advocates praised the move as one designed to ensure families will not be torn apart.
But Obama also received heavy criticism for what some called an overstep of his constitutional authority.
Both of Indiana's U.S. senators opposed the executive order, as did the Indiana attorney general.
The lawsuit echoes those concerns, alleging the president does not have the legal authority to take such action.
"This lawsuit is not about immigration," the lawsuit reads. "It is about the rule of law, presidential power, and the structural limits of the U.S. Constitution."
The complaint calls Obama's order an unlawful, unilateral suspension of the nation's immigration laws.
In a statement, Gov. Mike Pence, R-Indiana, re-emphasized that Indiana's participation in the lawsuit is not about immigration, but about the denial of states' rights to be represented through its members of Congress.
"While reasonable people can differ on ways to improve our nation's broken immigration system, the President's unilateral action was an unacceptable end run around the democratic process," Pence said.
Pence says the lawsuit isn't about immigration, but about the rights of states to be represented in policy making decisions through Congress.
The Attorney General's office will not take part in the suit. Spokesman Bryan Corbin says the AG's office has given its consent for Pence to hire outside counsel to handle the issue. Corbin says using outside counsel at the trial court level is appropriate in this case.
Sen. Dan Coats, R-Indiana, said he supports Gov. Pence's decision to join the lawsuit.
"President Obama's role is to faithfully execute the law, not alter or ignore it as he sees fit,," Coats said in a statement. "I am hopeful that the legal challenge filed by Indiana and many other states will be successful."
The lawsuit was filed in a U.S. district court in Texas.