Multiple people were wounded early Sunday, June 17, 2018, when shooting broke out at the Art All Night festival in Trenton, New Jersey, early Sunday, sending people stampeding from the scene and leaving one suspect dead and at least 20 people injured, a local prosecutor said. (Paige Gross/ NJ.com/The Star-Ledger via AP)

Over the past decades, the United States has faced more and more mass shootings that are the result of neither criminal competition nor family violence: Columbine and Aurora in Colorado; Virginia Tech; Newtown, Conn.; Emanuel AME Church in Charleston, S.C.; the Pulse nightclub in Orlando; First Baptist Church in Sutherland Springs, Tex.; Mandalay Bay in Las Vegas; the one this year that sparked a protest movement at Stoneman Douglas High in Parkland, Fla.; Santa Fe High School, southeast of Houston. Today it is a mass shooting at a New Jersey arts festival.

More are surely coming. As Erica Chenoweth explained here at TMC in 2015, both mass shootings and terrorist attacks tend to lead to copycat attacks.

In response to this latest shooting, we are reposting our roundup of political science insights into subjects relevant to these shootings, including our post-Parkland coverage.

Will the increasing number of mass shootings prompt more gun regulation?

Mass shootings are often followed by public discussions about whether various gun policies might have prevented the violence. After the Charleston, S.C., church shooting, David Fortunato examined the claim that had parishioners been carrying guns themselves, they might have prevented their own deaths.

Danny Hayes explained — in one graph — why it’s so hard to pass gun regulation. Sarah Binder examined why we should expect congressional gridlock on regulating guns. Henry Farrell explained that if and when such regulations do pass, this is what it would take for them to be effective in reducing shootings.

After the Las Vegas shooting, in which one gunman killed 58 people and injured 546, Benjamin Newman and Todd K. Hartman showed us that the closer you live to the site of a mass shooting, the more likely you are to support regulating guns. They suggested that in a nation as vast as the United States, it may take many more such attacks, spread around the country, before there’s enough sentiment to pass national gun regulations.

Matthew Lacombe explained how the NRA “politically weaponized” its membership, developing a social identity for gun owners that came with the ideology and outlook about guns and freedom that they hold today. In this stance, gun owners are patriotic, upright citizens protecting freedom whose values are under attack by radicals and elitists who stand for a chaotic society.

Is that gun-owning identity linked to white racial prejudice? Alexandra Filindra found that white people who score high on racial resentment are more likely both to own guns and to oppose gun regulation — although not because they fear black violence.

Mark Joslyn and Donald Haider-Markel told us that Americans vastly overestimate the proportion of their fellow citizens who own guns — and explained why that makes regulation harder to pass. And Christopher Hallenbrook and Ryan Reed examined the contradictions between the NRA’s Hobbesian view of the world and its libertarian prescription about what to do about that.

When did guns become a partisan issue?

Joslyn and Haider-Markel have also shown that gun ownership used to be bipartisan, but no more — which now puts that political weapon primarily in the hands of Republicans. And yet, Steven V. Miller showed earlier in October that many Republicans still supported key types of gun regulation.

And Joslyn and Haider-Markel explored the idea that, increasingly, a gun culture has developed in which “gun ownership represents a cluster of values, such as strong individualism, distrust in government and personal freedoms” that are linked to the Republican Party. Two years ago, Eric Stern explained that people who live close to mass shootings become less likely to vote Republican.

Can the post-Parkland movement succeed in changing the U.S. relationship with guns?

Erica Marat told us that, based on her international research, you need two things for a successful anti-violence movement — and that the Parkland students have both. Independently, Erin Mayo-Adam looked at such social movements in the United States — and showed us that the Parkland students may have what it takes.

John Sides showed us some polling that most teenagers and adults think that arming teachers, that perennial suggestion, would be dangerous. Jason Miklian and Jennifer Oetzel told us why #BoycottTheNRA worked so quickly to get corporations to cut their ties with the organization.

Dana Fisher measured who actually attended the D.C. March for Our Lives and found — surprise! — that it wasn’t mostly young people. Meanwhile, Erica Chenoweth and Jeremy Pressman continued their nationwide assessments of U.S. protest attendance, with a special installment (aided by Kanisha Bond) on what the March for Our Lives looked like nationwide.

Why does the United States have so much deadly gun violence?

Brian J. Phillips examined whether “lone wolf” or terrorist groups are more deadly, and found that the answer depends on the country, with the United States being the rare nation where individual attacks are more common and usually deadlier than attacks by groups.

And Kieran Healy showed us in one graph that, yes, the United States is an unusually violent society, compared with other rich capitalist democracies — with more violent deaths from random attacks because it’s so easy to buy highly lethal guns. As he wrote, “Using a truck as a weapon is just less efficient than using a weapon as a weapon.”