One of the brothers charged in the August shooting death of mother-of-four Nykea Aldridge in Chicago, which prompted a controversial tweet from Donald Trump appealing for black support (“VOTE TRUMP!”), was released only two weeks earlier on a firearms violation. Ditto the murderer of 15-year-old Hadiya Pendleton, whose 2013 killing was adopted as a symbol by the Obama administration. Her killer had also recently been released on a weapons charge. Chicago Police Superintendent Eddie Johnson last month explained reality to the Chicago Tribune : Of the 1,400 people on the city’s “Strategic Subject List” of those believed responsible for its gun violence, most have been arrested and released multiple times on gun charges. By one count (that of the Chicago Sun-Times) 75% of those booked on gun violations in the first three months of 2016 were back on the streets by June. “Clearly, [gun felons] don’t think there’s a consequence to their actions,” Supt. Johnson said in a public news conference. “And to be quite honest, we’re showing them that there’s not. If we’re not going to keep you in jail because you choose to use a gun, then what are we doing?” In New York in the heyday of stop-and-frisk, these killers would not have been released-something noticeable even to a real-estate developer not otherwise known for the depth of his public-policy acumen. Those convicted on firearms violations were hit with serious jail time. Even when aggressive stop-and-frisk didn’t result in a conviction, an illegal gun was confiscated, and word went out that packing an unlicensed weapon was likely to be unavailing given the city’s unrelenting focus on gun violators. All this was part of a deliberate strategy in the 1990s to reduce New York’s then-towering murder rate. Chicago’s murder rate today is a bit of an anomaly in an America where crime has been dropping until recently, but it’s not a product of the city not knowing what to do. To many liberal and African-American activists not living under immediate threat of gun violence, however, stop-and-frisk has become unacceptable. They reject the tactic because police, some of whom are white, would inevitably be stopping mostly black and Hispanic citizens on the street in search of illegal weapons. Thus Mayor Rahm Emanuel, who sees his political career going down the drain due to the killings, has every reason to believe his career would only go down the drain faster if he took steps that he knows would save Chicagoans’ lives. If he has any doubt, he need only look at the New York Times ‘s home page on Friday. Its headline on Mr. Trump’s endorsement of stop-and-frisk judged the most urgent lesson for the public to be: “Trump Crime Plan Seen as Hitting Minorities Harder.” At bottom, it’s this rottenness of American political culture that allows Mr. Trump, for all his flaws as a candidate and human being, to find traction with so many voters. Not because he’s a uniquely attractive individual, but because he’s uniquely willing to violate the political taboos and challenge the status quo. Indeed, his most insidious offense may be his suggestion that some problems aren’t intractable. Take another example of rottenness. On Thursday, U.S. Attorney Preet Bharara indicted nine associates of New York Gov. Andrew Cuomo for bribes in connection with development grants for upstate. The region’s economic problems for the past half century are not due to a lack of government-backed capitalism, such as Gov. Cuomo’s adopted fetish for nanotechnology. Upstate’s problems stem from tax, regulatory and land-use policies designed to flatter the priorities and prejudices of wealthy New York City liberals. The immediately relevant example is Gov. Cuomo’s ban on fracking, undoubtedly undertaken with an eye on burnishing his presidential bona fides with his party’s liberal greens. His subsequent blather about nanotechnology, his unlimbering of state development funds, were never seriously meant to compensate residents on the jobs and wealth they’d be forgoing. These gestures (with taxpayer money) merely give the governor something to say when the subject comes up. Everyone’s entitled to the presumption of innocence, and much of what is corrupt and rotten in politics is not illegal. Still, no one should be surprised when such offerings produce mainly a scramble among his donors and aides to allocate the benefits to themselves. Not every problem can be solved with a modest policy tweak. Sometimes a wrecking ball is needed. Pollsters, in a moment of insight, have lately taken to describing the Trump voter as a compos mentis risktaker open to a high-risk, high-reward gamble. This seems to get it about right. What kind of president would Mr. Trump make? We have no idea and there may be only one way to find out. But, whatever the case, America has deep problems of bureaucratic corruption, sterility and incompetence that increasingly argue for a wrecking ball.