His analysis of why federal gun control laws aren’t enacted after mass shootings is less interesting that his prescription for changing that in the future (at the link).
I think it is natural to expect when there is a tragic mass shooting event that opinion (may) become decisively more supportive of gun control legislation. But what we actually see is, if anything, rigidity.
In our study, we tested whether people living near mass shooting events were likely to shift their views. What we found is that Democrats became even more supportive of stricter gun control legislation, while Republicans became even more opposed to it. I think the reason for this is that each tragic mass shooting brings an intense debate about gun control, and partisans mostly follow the lead of what the politicians from their own party are saying about the issue.
– Tufts professor Brian Schaffner in Why mass shootings don’t lead to gun control