All mass shootings share one common element and only one: every one involves a gun.
There are many other factors, many other considerations, many other issues, and many other public policy matters play in mass shootings, but none of them are involved in all shootings. These include: whether the shooter was bullied; the type of gun used; the race of the shooter; the race of the victim; the mental health of the shooter; the age of the shooter; the age of the victims; whether the shooter had a troubled background; the location of the shooting; the time of the year; the economic conditions of the shooter; the economic conditions of the victim; and a myriad of other factors.
Some of these elements and considerations will be found in each mass shooting incident. Often you can find several of them. But there is only one element that is common to all mass shooting incidents – the shooter used a gun.
Any politician who is unwilling to recognize this basic fact is not fit to serve in office.