Politico: When President Barack Obama took office, he inherited some of the greatest challenges the nation has ever faced, with a potential economic collapse and climate crisis topping the list. He also faced a public that had placed its hopes in his ability to change the way America operates, from revitalizing the economy and reforming health care, to ending our expensive addiction to oil and reining in dangerous global warming pollution. In June 2009, it felt as if we were well on our way …