After four decades, the "war on drugs" has lost its appeal -- including to some of the country's biggest arbiters of moral behavior: churches.

The war on drugs became a thing under Nixon in 1971. Reagan passed the Anti-Drug Abuse Act of 1986 while his wife championed the "Just Say No" campaign. Under Clinton, incarcerations rose to historic levels. But today, the Obama administration has called the war on drugs "counterproductive, inefficient and costly," while some of those hoping to take his job -- like Hillary Clinton and Rand Paul -- are calling for a new approach to handling the issue.

And now, even churches are even joining in. The New England Conference of United Methodist Churches passed a resolution recently calling for an end to the war on drugs. In a statement, the group said the war hasn't been effective and it's led to unintended consequences like crime.

The conference includes more than 600 churches. That's a drop in the bucket in a country with hundreds of thousands of churches, but they're not alone. In 2014, Christian leaders in Tennessee and Indiana also called for an end to the war on drugs.

Churches would be a significant loss for the war on drugs, which has already been losing ground among all Americans -- and increasingly politicians too.

Since the early 2000s, the percentage of Americans who who think the country has made progress coping with the problem of illegal drugs has dropped.

At the same time, mass incarceration and racial disparity in the justice system have become major political issues, and acceptance of marijuana has increased.

It's a perfect storm of sentiments that could lead to an abandonment of some drug-enforcement policies and a search for a new solution. In some states, it's urgent. California faced a federal court-order to reduce its jail population, and in November, voters there passed a measure that downgraded drug possession cases from felonies to misdemeanors, making thousands eligible for release.

Current and former Republican governors have also looked into sentencing reform -- if not specifically on drugs -- including Rick Perry (Texas) and Chris Christie (New Jersey), who spoke on the topic at CPAC. Georgia's Nathan Deal, Indiana's Mitch Daniels, Louisiana's Bobby Jindal and Ohio's John Kasich have also signed legislation or supported programs aimed at lowering prison populations.

Given the prevalence of drug-related arrests, those are often cited as a way to quickly shrink the prison population.

According to FBI data, an estimated 13 percent of all arrests in the United States in 2013 were drug-related, the highest percentage for any category, and 47 percent of all drug abuse violations were for marijuana sale, manufacturing or possession. Meanwhile, the percentage of Americans who have tried marijuana has slowly risen to 38 percent in 2013, as a few stats have legalized recreational use of the drug.

That's still a minority of the U.S., but even those who have never used pot are more comfortable with it. Since 2013, a majority support legalizing it.

Those who support legalization are more likely to be liberal (73 percent who support it) or moderate (58 percent), while only 31 percent of conservatives do, according to Gallup.

For that reason, GOP  presidential candidates and churches seem to be the next logical supporters of rolling back the war on drugs. And as they continue to trend in that direction, it spells bad things for the decades-old war.