Senator James Inhofe displays a snowball as evidence that climate change isn’t real. PHOTOGRAPH BY C-SPAN

People will recall that, not so long ago, Senator James Inhofe, Republican of Oklahoma, in order to conclusively demonstrate that claims of man-made climate change were false, made a snowball after a February storm and threw it on the Senate floor. I demonstrate it thus! If I see frozen water, how can the planet be warming? What was so beautiful about this demonstration was that it did not even depend on a snowball made out of season, one packed and tossed, say, in September or April—this was a mid-winter snowball, and it still refuted global warming, for once and all.

Anyone who follows the debate on any public issue discovers that the snowball-in-the-Senate style of argumentation persists, with the same note of smugness—that’ll show them! It most often comes from the same political direction, or party, and with the same disconnection from all familiar standards of evidence and argument. In the debate about the necessity of bringing America into agreement with the rest of the civilized world on the issue of guns and gun killings, there are some persistent snowballs-in-the-Senate that keep getting thrown, which need to be mopped up as they melt.

Snowball No. 1: There is doubt or mystery or uncertainty about whether national gun control can actually limit gun violence. No, there isn’t. The real social science on this, published in professional and, usually, peer-reviewed journals, is robust and reliable, while fake or ersatz social science that proposes to show the opposite has been debunked many, many times. Of course, to say that the social science is settled is exactly not to say that one or two authority figures are in dogmatic possession of the truth—that’s not what makes it science—but that a broad community of people who have taken the trouble to study the evidence and open their data to each other have come to something close to a consensus. More guns mean more homicides. More guns mean more gun massacres. More guns mean more death. Common sense confirms what social science demonstrates: there really have been no gun massacres in Australia since Australia decided to act to stop gun massacres from happening.

Snowball No. 2: Levels of violent crime have been receding in America in recent years, so guns can’t really be a problem. This decline is real—but it is real everywhere in the Western world. The remarkable point is that American gun violence persists at its astonishingly high levels in spite of the general decline in the rich world of violent crime. You have to accept a uniquely narrow view not of human nature but of American character—that Americans are so uniquely violent, so paranoid and hate-filled, so incurably homicidal, that they will keep killing each other no matter what laws exist—to believe that the same simple social restraints that have ended epidemic gun violence elsewhere won’t work here. It would be more American to be more optimistic about Americans.

Snowball No. 3: Gun laws solve nothing because terrorists, whether in Paris or San Bernardino, aren’t the sort of people who care about or obey them. This snowball might properly be restated as follows: if a pickpocket steals your wallet on the bus, repeal the laws against pickpockets. If terrorists and criminals do still get guns, despite existing gun laws, there is no reason to have gun laws at all. But the goal of good social legislation is not to create impermeable dams that will stop every possible bad behavior; it is to put obstacles in their way. The imperfection of a system of restraints is an argument about the imperfection of all human systems. It is not an argument against restraints. What’s more, the special insight of recent criminology is to show that low walls work nearly as well as high ones, and are obviously much easier to build. Making any crime harder usually makes it much harder. If the terrorists in San Bernardino had had to work as hard at building guns as they did at building bombs, perhaps the guns would have worked as badly as the bombs did. (And, surely, it is a good thing that they were not able to go to a bomb store, or a bomb-owing middleman, for pre-made bombs.)

Snowball No. 4: There are already so many guns in circulation in the United States, and their owners are so determined to keep them, that introducing limits would have no practical effect. Determined social movements against what seemed to be fixed features of social life often work—to a first approximation, they always work, which is why the modern history of liberal societies has the generally happy arc it does. Piecemeal social reform tends to be slow, but it tends to be successful. (Many manageable middle-range changes, from ammunition control to "smarter" and more secure guns, have been suggested as passable paths to gun sanity.) One need look only at the history of smoking or of car safety to see that this is so. Cancer caused by cigarettes and deaths caused by traffic fatalities, which were once fixed and ubiquitous features of American life, have been vastly reduced by gradual reform. A full-court press against gun massacres, at local and state and federal levels, has already begun; the more it goes on, the safer we will become.

Snowball No. 5: Even if gun control were a good thing, the Second Amendment renders its achievement impossible. Not so. In 2008, the Supreme Court, by a vote of 5-4, decided the case of District of Columbia v. Heller in favor of the view that the Second Amendment guarantees a right to private ownership of weapons. Justice John Paul Stevens, appointed by a Republican President, in a dissent joined by three other justices, rightly found this view astounding and radical, writing that the Constitution speaks only to gun ownership within the context of a militia. But even the Heller majority agreed that the right it had conjured up was far from unlimited: there could still be conditions and licensing requirements and limits on where one could carry a gun. (Just last week, the Court declined to hear a challenge to a ban on assault weapons and large-capacity magazines in Highland Park, Illinois.)

And so even, according to the new view espoused by Heller, the rational test of actual experience should still trump the Kabbalah of eighteenth-century-word scrutiny, however exciting it may be to pseudo-scholarly minds. Does anyone believe that Madison and Mason, stumbling into the first-grade classroom where modern assault weaponry had blown apart twenty six-year-olds and six of their terrified caretakers, would then say, “Well, too bad—but, yes, that’s exactly what we meant by the right of the people to keep and bear arms”?

Snowball No. 6: Gun rights are a necessary hedge against tyranny. Ted Cruz has been throwing this snowball around quite a bit, strange as it is to hear a senator praise preparations for acts of terrorist sedition. This was, as it happens, exactly the argument of slave owners of 1861, well answered by Lincoln, and then by Grant.

If there is a risk to democracy it might be, instead, in the way the routine of gun violence and terrorist horrors like San Bernardino brutalize us as a people, and the way the paranoia they provoke changes our sense, to use one of the President's favored phrases, of who we are. Which risks are worth taking, and which demand a response, is a subject for grownup people to debate on a long winter night, with the snow drifting safely outside, where it belongs.