"NOTHING is more powerful than millions of voices calling for change," President Barack Obama said on March 28th, as he pushed—perhaps more for form's sake than with any hope of success—for tighter gun controls in the wake of last December's school shooting in Newtown. The truth is that gun control is going nowhere, and one reason is that the millions of Americans in favour of gun control do not live in the right places. Support for gun control is geographically and racially concentrated in ways that sap the movement of political power. And that disparity of opinion is linked to another reality: there is no national consensus on guns because different bits of America experience such wildly differing rates of harm from guns.

A valuable and sobering piece of research by the Washington Post on March 24th put some hard numbers behind the reality that everyone in the gun debate knows but finds hard to discuss. Rural and urban Americans, as well as blacks and whites, might as well live in different countries when it comes to their exposure to gun violence. After crunching the data, the Post found the following death rates per million people per year: gun homicides with black victims—151 per million, gun homicides with white victims—15 per million. When the 50 states are examined one by one, the disparities are even more stark: rates of fewer than ten gun homicides per million whites are recorded in Idaho, Wyoming and Utah. In Missouri, the research found a gun homicide rate of 308 per million blacks.

That helps explain polling that finds 78% of blacks supporting stricter gun controls, as opposed to 48% of whites.

These disparities are worth bearing in mind when examining the latest opinion polls which show support for gun control falling sharply in specific groups after a brief post-Newtown peak. CNN's analysis notes:

"Opinion on gun control was fairly steady over the past few years, but seemed to spike after the Connecticut shootings," CNN Polling Director Keating Holland said.... "In the immediate aftermath of the shootings in Connecticut, the number of rural Americans who supported major gun restrictions rose to 49% but now that support has dropped 22 points," Holland said. "Support for stricter gun laws dropped 16 points among Americans over 50 years old in that same time."

One way of describing post-Newtown opinion is that a shocking event briefly closed the divide between Americans who live with high rates of gun homicide and those who do not. But now the gap has re-opened. Tellingly, a minimum-ambition alternative offering on gun control being crafted by Senator Charles Grassley, a Republican from Iowa, will reportedly focus on tougher federal controls on criminals who smuggle guns to other criminals (ie, a form of gun control seen as aimed at urban gangs, far from Iowa), and tougher school security (addressing a form of rare gun violence that inspires disproportionate fear nationwide).

So should rural or white Americans care about gun murders? Yes, if they care about their fellow Americans. But if that is not enough, the recent number crunching has brought more precision to another bleak reality. If whites in rural Wyoming do not kill each other with guns very much, they kill themselves at horrible rates. The Post's analysis found gun suicide rates of 162 per million whites in Wyoming, and found that overall suicides are more common in states with high levels of gun ownership.

Nationally, the gun suicide rate is 75 per million whites per year in America, and 27 per million blacks, according to the Post's numbers.

A caveat. Suicide is a complex problem, and deserves more analysis than can be fitted into a single blog post. Suicide rates are affected by everything from demographics to economics, culture and mental-health-care provisions. But there is a lot of research to indicate that death rates are affected by the availability of methods of suicide that leave no chance for second thoughts (eg, by calling an ambulance after taking an overdose).

A final note. Even looking only at white and rural Americans, these are still high rates of gun death.

Gun-rights advocates are often angered by comparisons with Britain, a country in which handguns and semi-automatic weapons are essentially impossible to own privately, since a spate of mass shootings in the 1990s. A cottage industry has grown up explaining that America's many thousands of gun homicides a year include a few hundred cases of justifiable homicide, and that some noisy British television presenters working in America have understated British gun murder rates.

It is also important to note that democratic deference must be paid to the overwhelming majority of Americans who broadly support the right to bear arms privately. America is America, and its history and culture must be respected in any discussion of gun control.

But here are some numbers, for comparison, that do support an observation that this reporter has made before: the form of gun control that works involves no guns, even if that is not the sort of gun control that will ever be agreed in America.

Fatal injuries involving firearms offences in England and Wales in 2011: 42. Homicides in England and Wales involving firearms in 2011: 39. Suicides involving firearms in England and Wales in 2011: 90.

The population of England and Wales in 2011 was about 56.1m. That gives the following rates: firearm crime fatalities—0.75 per million; gun homicides—0.7 per million; gun suicide rates—1.6 per million.

Or put another way, residents of England and Wales have a gun homicide rate 21 times lower than that among white Americans, and 215 times lower than that among black Americans, and a gun suicide rate 47 times lower than that among white Americans.

Other forms of murder and suicide do not make up the difference. The overall American homicide rate in 2008 was 54 per million inhabitants per year. The overall homicide rate in England and Wales in 2011 was 9.6 per million. The overall suicide rate in America in 2009 was 117 per million. The overall suicide rate in England and Wales in 2011 was 87 per million.