Click-and-drag inside expanded story shouldn't try to move the story

When I click and drag inside an expanded story (anywhere that’s not inside a text box; I discovered this trying to copy text from a comment), the system interprets this as trying to move the story. I expect a click-and-drag operation to move a story only when I’m clicking and dragging on the (unexpanded) story itself, not a field inside the story. In particular, any text anywhere inside an “edit story” element should be selectable without having to resort to the browser developer tools.