It is possible that the high point of this week in Washington came when Senator Dianne Feinstein told Senator Ted Cruz to stop treating her as if she were in middle school.

Let me set the stage. First, pretend you’re Feinstein. You started your political career in San Francisco. While you were on the Board of Supervisors in 1978, your colleague Harvey Milk and Mayor George Moscone were assassinated in City Hall. You were the one who discovered Milk’s body.

You arrived in the Senate with an understandable interest in gun violence. The ban on assault weapons you successfully sponsored has long since expired. You’ve been working on a new one for almost a decade, and, after the Sandy Hook slaughter, it looked for a minute as if there might be a chance.

But, as the immediate impact of the tragedy faded, the assault weapons ban lost traction. This had nothing whatsoever to do with the power of the opponents’ arguments, which seem to get weaker by the day. The big pitch of the anti-ban lawmakers is that people need assault weapons for self-defense. But there’s a distinct shortage of examples of when they’ve worked better than a normal rifle or pistol.