In short, the city, reeling from 392 murders last year, is a sensible place for a politician to talk about how to crack down on violent crime. Sen. Hillary Clinton availed herself of the opportunity Friday, unveiling a crime initiative in which she pledged that, if elected president, she would “focus on cities with high homicide rates—and cut those rates in half.”

Could she? Like many other major American cities, Philadelphia suffers from a toxic mix of poverty and addiction that plagues communities where opportunities for education and employment are too few and too far between. Most criminologists agree that these factors help drive violent crime—a problem that is often exacerbated during economic downturns. Clinton says she will target specific high-crime cities where she will deploy more police using “improved technology and tactics”; bestow grants for reducing gang violence and drug markets; improve community partnerships with police; and spearhead a federal initiative to crack down on gun trafficking.

But would any of that come close to cutting the murder rate in half? Jake Sullivan, Clinton’s deputy policy director, tells NEWSWEEK that the 50 percent murder-rate-reduction goal is “both ambitious and achievable with the right resources and right strategies … She looked at New York’s success in reducing murders from more than 2,000 to less than 500 and other examples of successful efforts, including recent ones in Cincinnati and Chicago, and concluded that 50 percent was the right figure.”

David Kennedy, a professor at New York’s John Jay College of Criminal Justice who has worked with many cities to reduce gang violence and open-air drug markets, helped Clinton’s team design the proposal. Kennedy says cutting the crime rate in half in Philadelphia and cities like it would not be difficult with the right programs in place. Kennedy worked with the Boston Police Department during the 1990s, when the city achieved a dramatic reduction in homicides (from 152 in 1990 to 31 in 1999). The program he launched there, known as Operation Ceasefire, is one of the centerpieces of Clinton’s plan. Under that program prosecutors, police, gang outreach workers and social service agencies sat down together with gang members, told them violence would be met with punishment, and followed up by offering help to kids who wanted it and cracking down hard on those who kept shooting.

While Ceasefire surely made a difference in Boston, there may well have been other factors at work in easing the violent crime rate. An economic renaissance in the ’90s helped cut the murder rate dramatically in a number of major cities—New York, Houston, Dallas, Los Angeles, San Diego and Detroit among them. Those conditions may be hard to replicate in the wake of the subprime mortgage mess and credit crunch that have brought the American economy to the brink of recession. But Kennedy still thinks big cuts in the murder rate are possible. “I think we could do better than half,” he says. “It’s quite clear that deliberate action made a big difference in violent crime.” Kennedy points to a Ceasefire program he launched in Cincinnati last April that appears to be working; homicides are down by 45 percent over last year at this time.

Andrew Karmen, a colleague of Kennedy’s at John Jay and the author of “New York Murder Mystery: The True Story Behind the Crime Crash of the 1990s,” believes the murder rate is fueled by factors beyond the president’s control. “To use Bill Clinton’s phrase, ‘It’s the economy, stupid’,” Karmen says. Having studied New York City in the age of crack, Karmen came to the conclusion that factors such as an influx of law-abiding immigrants and the booming economy helped end crack’s scourge and curtail violence in the city—factors that often get overlooked when politicians praise the aggressive police tactics typically credited with cutting the homicide rate in the Big Apple. Al Blumstein, a criminologist at Carnegie Mellon University and the author of “The Crime Drop in America,” says that if Hillary Clinton reaches the White House and her administration is willing to pour enough resources into the cities it targets, she could achieve dramatic declines. But he also cautioned that the cuts in violent crime rates in the ’90s were more a result of a strong economy and the end of the crack era than of policy initiatives.

Clinton says that she will rely in part on a “reinvigorated” COPS program to achieve her 50 percent cut in the murder rate. But Blumstein says that the original COPS program, a Bill Clinton initiative that put 60,000 more police officers on the street, was found by the General Accounting Office to have had a “modest” impact on violent crime.

Clinton’s plan for halving the murder rate also relies on a federal initiative to crack down on illegal gun trafficking, in part by repealing a piece of legislation known as the Tiahrt Amendment (named for Kansas Rep. Todd Tiahrt, its main sponsor), which prevents the Bureau of Alcohol, Tobacco, Firearms and Explosives from sharing gun trace data with city police departments trying to track weapons used in the commission of crimes. But that could be an uphill battle. A coalition of big-city mayors led by New York’s Michael Bloomberg have been unable so far to persuade the Democratic majority in Congress to overturn the Tiahrt measure.

Clinton’s crime initiative no doubt makes for good campaign politics. But translating it into policy is another matter.