It was a year ago this month that President Barack Obama began losing voters. In the 12 months since, he has had legislative victories that appear – especially in the case of health care – to have cost him large amounts of both political capital and political support. A comparison of the public’s views of him then and now tells us a great deal about the shape of American politics and how difficult it is for any president, even one as politically gifted as Barack Obama, to surmount the nation’s deep political and ideological divisions. [Snip] On Election Day 2008,...