Republican presidential nominee Donald Trump thinks the best way to stop crime in black communities is to broaden the use of stop and frisk, a policing tactic that has been proved to be discriminatory against blacks and Latinos.

In an excerpt from a Fox News town hall billed as a “meeting on African-American concerns” and scheduled to air Wednesday night, Trump was asked how he would address “black-on-black crime.”

Trump replied that he “would do stop and frisk,” a practice heavily championed by former New York City Mayor Rudy Giuliani (R), who is now a prominent Trump supporter.

Trump’s claim that “in New York City, it was so incredible the way it worked” isn’t quite accurate. The tactics used there have been broadly condemned for disproportionately targeting blacks and Latinos while only incrementally reducing crime.

It seems unlikely Trump’s endorsement of such practices will help the nominee’s standing with black voters.

In 2013, a federal judge ruled the practice was being used unconstitutionally in New York, calling it a “policy of indirect racial profiling” because the New York City Police Department disproportionately targeted black and Latino men during routine traffic stops. In her ruling, Judge Shira Scheindlin wrote that stop and frisk was “a demeaning and humiliating experience” for communities of color.

“No one should live in fear of being stopped whenever he leaves his home to go about the activities of daily life,” she wrote.

Later that year, an investigation by the New York state attorney general found that only 3 percent of traffic stops “led to guilty pleas or convictions at trial” and only 0.1 percent were for violent crimes.

Ending stop and frisk as it had been used in New York was a top concern for the city’s current mayor, Bill de Blasio (D). The mayor told reporters Wednesday that Trump’s call to reinstate the methods previously used in the city and apply them across the country was “appalling.”

De Blasio makes rare visit to NYC press corps in City Hall's room 9 to dump on Trump's call for nationwide stop and frisk. "It's appalling." pic.twitter.com/qbofi1hrZC — Anna Sanders (@AnnaESanders) September 21, 2016

"He literally does not understand what he's talking about." -@BilldeBlasio — Erin Durkin (@erinmdurkin) September 21, 2016

Over the last few years, the NYPD has severely cut back on traffic stops, from a record high of almost 700,000 in 2011 to about 22,000 last year, according to data from the New York Civil Liberties Union. In a sign that it was reforming its practices, the NYPD warned officers in a memo last year that they need a “minimal level of objective justification” to make a stop, and they cannot make a stop simply based on a “hunch.”

Trump’s proposal drew quick condemnation from city council speaker Melissa Mark-Viverito. “Once again, Donald Trump is having trouble with the facts,” she said in a statement. “Stop and frisk as it was applied in New York City was unconstitutiona l, it didn’t reduce crime and it severely corroded the relationship between the police and the communities they serve.”

Trump’s campaign suggested the comments were aimed only at Chicago.

“Concerned about the ongoing, tragic violence in Chicago, Mr. Trump, along with many other Americans, believes that ‘stop and frisk,’ used successfully in New York City during the administration of Mayor Giuliani, saved lives and reduced crime,” Jason Miller, Trump’s senior communications adviser, said in a statement after the broadcast. “Mr. Trump believes that a locally tailored version of ‘stop and frisk’ should be used in Chicago to help reduce the city’s skyrocketing violence and make our Chicago safe again.”

This post has been updated with comments from de Blasio, Mark-Viverito and Trump’s spokesman.

Editor’s note: Donald Trump regularly incites political violence and is a serial liar, rampant xenophobe, racist, misogynist and birther who has repeatedly pledged to ban all Muslims — 1.6 billion members of an entire religion — from entering the U.S.