A Little Gravel on Both Sides
There is a quiet war on the printed page between the people who run their words right up against a long dash — jamming the thoughts together like traffic — and the people who leave a little room on either side.
Book publishers tell you to lock it tight. They want the em-dash to act like a solid iron gate, snapping you from one clause straight into the next without a moment to look around. But newspapers and old typesetters always left a gap. They knew that if you don’t give a long mark of punctuation its own clearing, the ink bleeds, the line breaks get messy, and the whole thing turns into a smudge.
Putting a space before and after the dash isn’t a mistake; it’s just a choice to let the text breathe. It matches the way a person actually talks when they hit a sudden shift in thought. You don’t just jump the track instantly. There is a beat there. A fraction of a second where the room goes quiet before you head off in a new direction.
Maybe it’s an AP Style habit, or maybe it’s just what happens when you spend your life looking at a horizon that doesn’t crowd you. Some layouts want everything packed tight and efficient, but there’s a lot to be said for leaving a little gravel on both sides of the road.