Since crime spiked in 2020, politicians and pundits have scrambled to figure out what they think is the root problem: whether Republicans or Democrats are more to blame.
Conservatives blame soft-on-crime policies in big cities, noting that many Democratic-run cities have long suffered from high crime rates and that many such places experienced particularly large spikes over the past four years. Liberals counter that, at the state level, it’s Trump-voting states that have higher murder rates, which they largely blame on irresponsible gun laws.
In a new Manhattan Institute brief, we try to calm things down a bit—and urge those worried about crime to think about which policies work, not about whether the politicians implementing them happen to be Democrats or Republicans.
To start with, using publicly available homicide data, it’s easy to confirm empirically what both sides of the debate have said. In counties with at least 200,000 population (smaller ones are frequently missing data), more Republicans tends to mean less crime: if we look across such counties, every ten-point increase in Trump’s share of the 2020 vote corresponds to a 14 percent lower homicide rate. But at the state level, the results flip: A state with ten points higher Trump support has, on average, 25 percent more homicides.
The raw data, therefore, allow both sides to claim what they are claiming for political reasons. But we can take things further, by using statistical models that account for some obvious confounding factors—such as each place’s racial composition, age demographics, urbanization, and income, all variables with obvious and well-documented relationships with crime. The more relevant question becomes: What happens to the link between Trump support and crime if we compare places that are relatively similar?
The answer is, at both the state and county levels, the previous relationships disappear. Here’s a “before and after”-style comparison:
The Relationship Between Trump Share and Homicide Rates
As we write in our brief, the point is not that the model we came up with is the “right” one. One could defend other ways of approaching the data. Rather, we want to emphasize several crucial points.
First, consumers of social science should better appreciate that someone skilled in data analysis can often make numbers seem to say whatever they want—including, in this case, that Democratic-controlled areas have more crime, that Republican-controlled areas have more crime, or that political party makes no difference once basic control variables are accounted for. This doesn’t mean that one can simply ignore data and social science altogether. It means that, to understand truly any given social-science result, one must carefully consider the process through which the data were collected and analyzed.
Also, even if our model is hardly the only defensible approach, it does show that crime differences across states and counties are significantly driven by factors not directly under the control of state or local policymakers. The crime drop of the 1990s and recent spikes in homicide show that dramatic change is possible in a short period—but in studying crime rates at any given point in time, one must also consider the longer-term context. Further progress in this debate over which party is worse for crime will need to account carefully for these differences, ideally using more advanced research designs or natural experiments. For example, do purple states see surging gun violence if they switch from a Democratic governor or legislature to a Republican one?
Fundamentally, however, it seems to us that time would be better spent debating policy rather than politics. The two are not the same thing. New York is an interesting case in point here: it’s often cited as an extremely safe, extremely blue city with effective policing and tight gun laws—but Republican and independent mayors oversaw its transition from the far more violent New York of the early 1990s and before.
If we must discuss politics, we are stuck quibbling over which party gets the credit for New York’s admirably low murder rate; but if we are discussing policy, we can ask what New York did right during that era and urge other cities to emulate it. In the 2000s, two Democratic mayors of Los Angeles took the latter approach, bringing in New York’s Bill Bratton as the city’s police chief and enjoying a decline in crime thereafter.
Large and important literatures are available concerning gun control, policing and prosecution strategies, and much more—and we suspect that both parties might learn a lot more from studying that literature and pursuing further research than they would from further mudslinging and data manipulation.
Photo by Spencer Platt/Getty Images