I n Alaska, President Obama was in a very good mood. He visited the state in late summer to draw attention to the looming climate catastrophe the world faces, but with the exception of one big policy speech when he sounded as apocalyptic as any hemp-growing activist, he spent most of his three days up north beaming. “He’s happy to be out of his cage,” one aide joked. Others credited the buoyant U.S. economy or the fact that the president had just learned that he had secured enough votes to protect the hard-fought nuclear deal with Iran from being derailed by Senate Republicans. Whatever the reason, you could see the cheerfulness in his face the moment he stepped out of his armored presidential limo at Elmendorf Air Force Base in Anchorage, where the air was hazy with smoke from the wildfires that had burned millions of acres in Alaska. The president was all smiles, shaking hands with local pols and then bounding up the stairs into Air Force One. No suit and tie, no sir — today, on what was the third and final day of his trip, he was dressed for adventure in black outdoor pants, a gray pullover…