When asked about gun laws in the wake of Tuesday’s massacre at Uvalde’s Robb Elementary School, Georgia senatorial candidate Herschel Walker had an illuminating response: “What I like to — what I like to do is see it and everything and stuff.” That “illuminating” description may sound like a joke, but it’s not intended as one. If Walker, the Republican nominee, wants to “see” what enabled the deaths of 21 people, 19 of them children, the best way would be to examine peer-reviewed research on gun violence, right?