WASHINGTON — Someone was with Salvatore Marchese when he died of a heroin overdose, but no one called 911.
So his mother, Patty DiRenzo, a legal aide, began a quest to help make sure that others would not be afraid to make that call. She created a Facebook page, wrote New Jersey Governor Chris Christie nearly every day, and called all 120 members of the state legislature.
The grieving mother accomplished what would have been inconceivable a few short years ago, much less back when the nation launched its war on drugs: She helped pass a bill, signed by a Republican governor, that lets people get away with using drugs for the sake of saving lives.
The state’s new ‘‘good Samaritan’’ law, which immunizes from prosecution people who call 911 to report an overdose even if they are using drugs themselves, is part of an emerging shift in the country’s approach to illegal drugs.
Four decades after the federal government declared war on narcotics, the prevailing tough-on-drugs mentality is giving way to a more nuanced view, one that emphasizes treatment and health nearly as much as courtrooms and law enforcement, according to addiction specialists and other experts.
The changes are both rhetorical and substantive, reflecting fiscal problems caused in part by prisons bulging with drug offenders and a shifting social ethos that views some drug use as less harmful than in the past.
States are driving the trend. At least 30 have modified drug-crime penalties since 2009, often repealing or reducing tough mandatory minimum sentences for lower-level offenses, according to the Pew Charitable Trusts, which works with states and tracks the legislation.
One-third of the states now have a good-Samaritan law, with the majority enacted since 2012.
That is the same year that Colorado and Washington became the first states to legalize recreational use of marijuana. ‘‘There is certainly more momentum than ever before,’’ said Mason Tvert, spokesman for the Marijuana Policy Project, an advocacy group that projects that a dozen or more states are likely to legalize the drug within several years.
Change is also afoot at the federal level, where FBI data show drug arrests are down 18 percent since 2006, and the Obama administration tries to avoid the phrase ‘‘war on drugs.’’
The Justice Department is strongly supporting changes being considered by the US Sentencing Commission that would reduce sentences for most drug offenders, and the Senate Judiciary Committee recently passed a bipartisan bill that would cut them in half for some drug crimes.
No one is suggesting that the fight against drugs is over. Federal agents are still battling traffickers on the southwestern border, and the administration has taken steps against abuse of prescription drugs and other illicit substances. Polls show that even as a majority of Americans now favor legalizing marijuana, overwhelming numbers still oppose that step for cocaine and heroin.
And while many of the drug law changes have drawn bipartisan support, some prosecutors are opposing Attorney General Eric Holder’s efforts to eliminate mandatory minimum prison sentences for nonviolent drug offenders.
The marijuana legalization campaign has also faced resistance from former Drug Enforcement Administration leaders and other critics.
But after a generation of antidrug messages symbolized by the ‘‘Just Say No’’ campaign of the 1980s and enforcement accompanied by martial metaphors, experts say a broad consensus is emerging around a crucial distinction.
Under the new paradigm, they said, traffickers engaged in the business of drugs will still face long prison terms, while lower-level users will increasingly be viewed as addicts with a treatable illness.
‘‘States in particular are starting to make much bigger distinctions between personal use and commercial activity,’’ said Adam Gelb, director of Pew’s Public Safety Performance Project, who pointed out that some states have recently toughened penalties for large-scale drug sales while relaxing them for drug possession.
Douglas Berman, a law professor at Ohio State University and an expert on criminal sentencing, called the new landscape a strategic shift rather than a ‘‘retreat’’ from the antidrug war.
It was June 1971 when President Richard Nixon sent a special message to Congress and targeted drugs as America’s ‘‘public enemy number one.’’
It was the start of the war on drugs, which emerged as a reaction to fear of crime.
The crackdown rose in the 1980s under President Ronald Reagan as Congress, with bipartisan support, established mandatory minimum sentences for marijuana and other drugs.
The first stirrings of reform came in a few states in the 1990s, and concern grew nationwide about perceived racial disparities in enforcement of drug laws.
Congress in 2010 passed a law reducing disparities in sentencing practices. The measure also repealed a mandatory minimum sentence — for crack possession — for the first time since the Nixon years. But states and localities have led the way, including in the development of good-Samaritan laws.