Criminal justice issues have long been ignored by national candidates.

Unlike the days of Richard Nixon, Ronald Reagan, George H.W. Bush and, of course, Bill Clinton, crime has not been on the national radar. The reason is simple, violent crime has fallen to unprecedented lows.

But crime — or at least the rhetoric of crime — is back in the presidential race.

During Monday’s presidential debate Donald Trump pledged to bring stop-and-frisk to every town in America. Hillary Clinton said the courts have declared stop-and-frisk unconstitutional. Trump retorted stop-and-frisk was behind the dramatic decline in NYC murders, Clinton said murder is still falling in NYC.

They are both wrong.

Stop-and-frisk is a practice in which police officers stop and question a person based on reasonable suspicion and frisk that person for weapons.

In 2013, U.S. District Judge Shira Scheindlin called NYC’s stop-and-frisk tactics “indirect racial profiling.” The police used the tactic more than 4.4 million times between 2004 and 2012. The vast majority of the stops were of blacks, 52 percent, and Hispanics, 31 percent.

Judge Scheindlin did not say that stop-and-frisk was unconstitutional. She couldn’t. In 1968, the U.S. Supreme Court made it clear in Terry v. Ohio that stop-and-frisk was constitutional.

Judge Scheindlin instead focused on NYC’s tactics, “In their zeal to defend a policy that they believe to be effective, they have willfully ignored overwhelming proof that the policy of targeting ‘the right people’ is racially discriminatory and therefore violates the United States Constitution.”

Nowhere has the decline in violent crime been more startling than in New York City. According to the New York Times, there were 2,272 victims of murder in the NYC in 1990 — in 2015, there were 352. There are a number of theories as to why violent crime fell so dramatically. Some suggest that at the height of the surge in violent crime, crack cocaine dominated the streets. As crack fell out of vogue, violent crime fell as well. There is also the “broken windows” theory introduced in 1982 when criminologist John Q. Wilson and George L. Kelling published an article in The Atlantic Monthly. The broken windows theory is simple. If one window is broken in a building and left unrepaired, soon all the other windows would be broken and crime would take over allowing violence to become pervasive. The solution? Crime can be controlled if neighborhoods are maintained. In 1994, when Rudy Giuliani took office as mayor of NYC, violent crime was out of control. He hired William Bratton who had used some of Wilson’s ideas as the chief of the New York City Transit Police. The results were remarkable. New York’s success can also be attributed to efficiency and innovation. The New York Times reported that former Police Commissioner Raymond M. Kelly said, “success can be traced to eight years of programs like Operation Impact, which attacks stubborn crime plateaus, and the Real Time Crime Center, which feeds detectives instant intelligence.”

Murder in New York City increased six percent between 2014 and 2015. Although, according to Politifact.com murder is down in the last week, last month and last 12 months. As a result, the New York Daily News which wrote after Scheindlin’s decision, “Make no mistake — Scheindlin has put New York directly in harm’s way with a ruling that threatens to push the city back toward the ravages of lawlessness and bloodshed,” rescinded its position.

In a recent editorial, The Daily News wrote, “We are delighted to say that we were wrong.”

NYC police scaled back stops under former Mayor Michael Bloomberg and accelerated the process under Mayor Bill de Blasio. As a result, the number of stops reported by the police fell 97 percent from a high of 685,700 in 2011 to 22,900 in 2015.

Not only did crime fail to rise, New York’s crime rate continues to hit record lows.

— Matthew T. Mangino is of counsel with Luxenberg, Garbett, Kelly & George P.C. His book, “The Executioner’s Toll, 2010,” was recently released by McFarland Publishing. You can reach him at mattmangino.com and follow him on Twitter at @MatthewTMangino.