Pennsylvania Governor Ed Rendell ordered a special extension of the deadline to help Hillary Clinton have the time she needed to put together a full slate of delegates for th state, but despite that she still fell short by about ten people. Marc Ambinder calls it "more evidence that the Clinton campaign simply did not envision a delegate hunt until it was much too late." But why didn't they plan for this? Sam Boyd, an unusually bright college student, figured it out so one would think an entire campaign full of veteran political professionals might have noticed what was happening.
Matthew Yglesias is a former writer and editor at The Atlantic.