By Justin Webb
BBC News, Tucker, Arkansas
Supporters of President George W Bush say it's one of his greatest achievements: encouraging religious organisations to help with the provision of basic social services.
Bobby Lytle says the InnerChange programme has changed his life
The White House has doled out millions of dollars of public funding to these bodies - many of them representing evangelical Christians.
But in one area an effort is being made in the courts to stop the practice.
The "InnerChange Freedom Initiative" has seen evangelicals take over wings of prisons around the nation and set up special courses for chosen inmates.
Supporters say it cuts down repeat offending - but opponents say it is evangelism by the back door, paid for in part by the state.
So far the courts - in an important case brought in Ohio - have sided with those who oppose these schemes. The issue is expected to go all the way to the US Supreme Court.
So I visited a prison to find out what supporters and, crucially, prisoners themselves, make of the fuss.
Bobby Lytle is four years into a 17-year sentence for second degree murder.
Inmates who sign up to the scheme live in a different wing of the prison
His life up to now has not been a great success. But he tells me it has changed utterly thanks to the InnerChange programme at Tucker Correctional Facility, near Little Rock, Arkansas.
Four years ago, he says, "I took a man's life." And, he adds, "There is no going back from that."
In his previous life, he says, the slightest disagreement would have led him to violence. "I would have bust you up," he says.
Now Bobby says he wants nothing more than to contribute to the community. Violence is a thing of the past for him.
It sounds miraculous - and many supporters of this scheme would happily use that word.
The prisoners rise up as one to pledge their allegiance to Jesus and the Bible and to their new selves.
This is recognisably and unashamedly an evangelical Christian setting - but there is more to it than prayer.
In a class entitled Authentic Manhood, for instance, the inmates are taught how to treat women and children. They are taught things they never learned from their abusive fathers and disrupted families, and things that occasionally make them weep with sadness and recognition.
The teacher explains the aim of the good husband: to be a leader of the family but to earn that leadership, not demand it. The prisoners nod, they seem to get it.
The first time he attended the Authentic Manhood class, Christopher Elmore says: "I looked around the room and there wasn't a man there who didn't have tears in his eyes."
Chris Gilbert agrees: "If I was to get into a relationship I would know how to treat her - I know how to provide now."
What, then, is the problem?
Outside the InnerChange wing of the prison you can see the other buildings where the general population lives.
Carl Dawson says it was hard at first to leave the main prison
What campaigners for secular America say is that there should not be a religious test, a religious hurdle, that gets you from the violent misery of the other cell blocks at Tucker into this place.
The man who runs the scheme, Scott McLean, says that this is a misunderstanding.
He denies that there is a religious test. "In fact we have non-Christians here," he says, "and they are welcome to stay in the programme."
To sign up for InnerChange in Arkansas, inmates ideally have between a year-and-a-half and two years left of their sentence. Those with a longer time left before release are accepted if there is space.
The inmates must agree to core values - but those values are not exclusively Christian, Mr McLean says. Among them are integrity, responsibility, productivity and community.
The prisoners themselves tell you that the move from the main jail to the InnerChange wing is not easy. In fact, says Christopher Elmore: "This is the hardest time I have ever done."
Carl Dawson agrees, saying the act of coming here, moving out of the main prison, was a struggle for him.
Critics say it is unconstitutional for a religious scheme to be run in jails
He remembers being hugged by the inmates when he first arrived and wondering whether he should hit them.
Now, he believes the closure of the unit would be a catastrophe. "God knows what we would do," he says.
It is unlikely that any of these schemes will be closed entirely any time soon but in the future they may have to rely on charity.
The InnerChange inmates at Tucker Correctional Facility have a simple message for the outside world: whoever funds it, whatever arrangements are made to keep it legal and constitutional, please keep the scheme.
For them, it is salvation.
IFI operates programmes for men in Texas, Iowa, Kansas, Minnesota, Arkansas and Missouri. Women's programmes run in Minnesota, Arkansas and Missouri.