There’s a man, 68 years old when a federal government expert met him, who at the time had been admitted to one of Mississippi’s state mental hospitals 46 times in his life.

That man is an exemplar of the case the federal government will seek to make during a bench trial that’s scheduled to start today before U.S. District Judge Carlton Reeves in Jackson. Federal prosecutors will tell Reeves that the state of Mississippi is violating a 1999 U.S. Supreme Court decision called Olmstead, which found that “unjustified” confinement in a mental hospital violates the Americans with Disabilities Act.

“The evidence at trial will make clear that individuals with serious mental illness can be appropriately served in the community,” wrote Deena Fox, a lawyer for the Civil Rights Division of the Justice Department.

The state may not contest many of the facts to which experts testify. Instead, Mississippi’s defense boils down to: All those things may be true, but you still can’t legally make us change.

That’s overstating it some. Mississippi actually argues that it’s doing pretty well by many measures. But the bedrock of the state’s defense is a contention that the federal government is overreaching, trying to eliminate all state mental hospitals, and setting an impossible standard.

“Olmstead does not require states to deliver a mental health service system that has no ‘unmet needs’ or no ‘gaps’ in service,” wrote James Shelson, one of the private lawyers hired by Attorney General Jim Hood to defend Mississippi. “While such a system is a worthy aspiration of every state, it is unattainable, no matter how many injunctions courts issue.”

The state argues that the federal government is illegally trying to force a fundamental alteration of Mississippi’s mental health system, that it’s not required to provide any particular standard of care, and that the federal government hasn’t done enough to sketch out what changes it wants or how much they would cost.

Reeves already refused to dismiss the case on these grounds. However, the state may be aiming at the 5th U.S. Circuit Court of Appeals or the U.S. Supreme Court. If Mississippi wins, it could undermine the federal government’s ability to pursue Olmstead claims against other states.

The federal government argues much of the state’s position is bunk, though. For example, Fox cites a previous court ruling that says a state can’t assert a “fundamental alteration” defense unless it actually has a plan to comply with Olmstead.  Department of Mental Health Deputy Director Steven Allen testified in a deposition that he’d never seen an Olmstead plan for Mississippi.

The state later said that the department strategic plans are its Olmstead plan, but Fox said they “still do not include measurable goals.” Even if they did, she said the state can’t show the plans actually result in fewer people being hospitalized, noting inpatients have been steady at roughly 3,000 for the past five years.

More importantly, the federal government argues that the state already has effective community-based services, such as crisis intervention teams and what’s called the Program of Assertive Community Treatment, but just doesn’t offer them in enough places.

Fox wrote the state “cannot credibly argue that extending existing services to individuals who need them to avoid unnecessary hospitalizations is anything but a reasonable modification of its service system.”

The patients the federal experts interviewed are anonymous, so it’s unclear what happened to that 68-year-old man. But what happens in a federal courtroom in coming weeks could determine whether the federal government can force Mississippi to do more to send similar people outside the walls of state hospitals.

Jeff Amy has covered politics and government for The Associated Press in Mississippi since 2011. Follow Jeff Amy him on Twitter at twitter.com/jeffamy.