The key to understanding the Obama enigma of 2012, according to more than a dozen Obama associates interviewed by POLITICO during the campaign, is that the president enthusiastically approved the message of relentless attacks against Mitt Romney. But until the last week of the campaign — when optimism made a major comeback — Obama executed it mirthlessly and mechanically, at times reinforcing the “meh” vibe of his supportive but uninspired base…

“I get why he had to do what he did. It was smart politically. But he’s become the embodiment of the partisanship he once decried,” said The New York Times’s David Brooks, one of the few journalists to strike up a real relationship with Obama during his first term. “The dissonance [between Obama in 2008 and 2012] is so obvious. … Can you think of a president who ran more different campaigns the first and second times? I’ve tried. I can’t.”…

“[Obama] found his voice in 2008. That voice has, for the most part, been missing in 2012,” said CNN contributor David Gergen, who counseled presidents Gerald Ford, Ronald Reagan and Bill Clinton.

“This isn’t the kind of politics this man likes to practice. … Another factor is that he’s a moody person. Bill Clinton, for instance, was a much sunnier person. He let things roll off him more easily. You could see that during [Clinton’s] reelection campaign. … The clothes of this campaign, the negativity, don’t really fit” Obama.