THE LEARNING CURVE OF PRESIDENTS: Paul Greenberg writes:

There’s nothing like bitter experience to test glib theories. But presidents can be remarkably slow learners, such is the power of their more cherished — and fixed — ideas.

Following those ideas over the cliff tends to reduce politicians to explaining why their policies were really right all along, no matter how wrong they proved in practice. See Jimmy Carter — or, for that matter, Jefferson Davis. The first, and last, president of the Confederate States of America could still fill up two unreadable volumes explaining why his constitutional theories were absolutely right — even as he stood amid the ruins his theories had wrought.

Other leaders wake up just in time to shake off their delusions, reverse course, and avoid the worst.

Read the whole thing.™