The killing of Charlie Kirk at a public event has left people who speak in public shaken, and it points to a broader problem with political violence in America.

• Kirk was shot while doing the kind of open public event that political figures hold all the time.
• That has rattled other public figures, who now see the same risk in their own work.
• One of them faced an armed man at his own door last year while broadcasting.
• The pattern suggests the danger is not isolated but part of a rising trend of violence in American politics.

Outlook: Expect tighter security at political events and more pressure on both parties to cool the rhetoric.