It was crime that separated New Democrats from Old in the 1980s. Bill Clinton was determined that nobody would Willie Horton him. He backed the death penalty, endorsed longer sentences, and funded local police forces, all with a view to stopping crime by punishing criminals.

Then the crime rate fell. It fell suddenly, it fell fast, and it fell far. By 2010, rates of crime against person and property had fallen to levels not seen since the early 1960s. In New York City, crime rates tumbled even lower. The great crime decline reshaped cities, remade the economy, and transformed American politics.

As crime declined, the law-and-order issue faded—and the national Democratic party revived. A potent symbol of that revival: Michigan’s Macomb County, the famed barometer of white-ethnic backlash. This blue-collar suburb of Detroit had delivered landslide majorities to John F. Kennedy in 1960—and to Ronald Reagan in 1984. Pollster Stanley Greenberg conducted a series of focus groups in the county in the mid-1980s. At one, he read aloud a quotation from Robert F. Kennedy about the wrongs done to black Americans. “No wonder they shot him,” snapped one participant.

But between 1990 and 2010, the rate of violent crime in the state of Michigan dropped by one third. In 2008, Macomb County voted for Barack Obama over John McCain by almost nine points.

Emancipating Americans from the fear of crime emancipated Democrats from the need to position themselves against crime.

The death penalty has all but vanished from the blue and purple states. The state of California has not executed a criminal since 2006. Ditto North Carolina and Ohio. Illinois and Pennsylvania have not carried out an execution since 1999; Colorado and Oregon not since 1997.* The Democratic Party’s 2016 presidential front-runner, Hillary Clinton, has forcefully distanced herself from the tough-on-crime policies of the 1990s. “It’s time to end the era of mass incarceration,” she told an audience at Columbia University in April 2015.

She’s already getting her wish. The rate of incarceration in the United States peaked in 2007. California has moved especially fast: The rate of incarceration in the nation’s largest state has tumbled by almost 25 percent over the past decade, from over 450 persons per 100,000 to 350.

Day-to-day policing is becoming less intrusive too. In 2013, Bill de Blasio won election as mayor of New York City on a promise to end the stop-and-frisk policing of the Bloomberg and Giuliani years.

Maybe this should not have come as a surprise—but as law enforcement has relaxed, crime may suddenly have begun to rise again. It’s early to say whether we’re looking at a blip or a trend. But something big and ominous seems to be taking form across the country: