Biden would have still won throughout the south, of course. But what made Biden the presumptive nominee, in the end, was that people saw it as a two-person race, and in the south they gave Biden landslide after landslide after landslide, at a time when the Sanders team thought they'd be competitive in NC and VA, at least.

Some of that's probably Clyburn. Some of it's the resounding SC result that followed from it, but I wonder if Sanders might have hurt himself in the south a little more by skipping the Selma commemoration. If Sanders had done just a little better in the south he might have ended the night (after California eventually comes in) still holding a delegate lead. Then who knows what the narrative would have been by now.

It seems like they wrote off the south almost out of habit, maybe over hard feelings from 2016. But margins matter. You can't write anything off.