A woman cries during a candlelight vigil for the victims of the Wednesday shooting at Marjory Stoneman Douglas High School, in Parkland, Fla., Thursday, Feb. 15, 2018. (AP Photo/Gerald Herbert)

Over the past decades, the United States has faced more and more mass shootings that are neither criminal competition nor family violence: Columbine, Aurora, Virginia Tech, Newtown, the Charleston, S.C., Emanuel AME Church, the Pulse nightclub in Orlando, the First Baptist Church in Sutherland Springs, Tex., Mandalay Bay in Las Vegas. This week it is Stoneman Douglas High School in Parkland, Fla. 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.

Here’s a roundup of political science insights into subjects relevant to these shootings.

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.

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? Certainly, 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.

When did guns become a partisan issue?

Earlier this year, Mark Joslyn and Donald P. Haider-Markel showed 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, many Republicans still support key types of gun regulation.

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.

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 deadly than attacks by groups.

And Kieran Healy showed us in one graph that yes, the United States is an unusually violent society, compared to 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.”