I'm not surprised you missed the point in your ad hominem reply, but here is one example of a large city that reduced crime when a Republican was in charge:
https://www.nber.org/digest/jan03/w9061.html
What Reduced Crime in New York City
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Many attribute New York's crime reduction to specific "get-tough" policies carried out by former Mayor Rudolph Giuliani's administration.
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The contribution of such deterrence measures (the "stick") offers more explanation for the decline in New York City crime than the improvement in the economy, the authors conclude. Between 1990 and 1999, homicide dropped 73 percent, burglary 66 percent, assault 40 percent, robbery 67 percent, and vehicle hoists 73 percent. The authors' model manages to explain between 33 and 86 percent of those declines.
And for your information, I'm no fan of Trump. But he did say someone else with enough authority could fix Chicago's crime problem.
https://chicago.cbslocal.com/2017/07/28/trump-crime-problem-solved/
“I said what the hell is going on,” Trump recalled. He says he asked the officer, “How long would it take you to straighten out the problem?”
The Chicago police officer told Trump if he had the authority, only “a couple of days,” the president said. The Chicago officer told Trump the police know who all of the criminals are.
