Social media has blurred the lines between formerly distinct spheres of activity — emotional venting, public mourning, political organizing — and it is essential, especially in the wake of a tragedy that deserves a policy response, to make an effort to reconstruct those boundaries.

The massacre in Uvalde has left most of us feeling angry and frustrated and with a sincere need to express those feelings.

And because people express themselves in part through the content they click on and share, this expressive activity starts to drive the media agenda, which in part drives the political conversation. This means that a mass shooting immediately creates a high-profile content escalator:

• Something horrifying happened.

• Things like this tend not to happen in other rich countries with no guns.

• Things like this would not happen if there were no guns in the United States.

• In fact, tens of thousands of lives per year are lost to guns, and all those people could be saved if there were no guns.

• Why w…