Obama's right-hand man on "battle-hardened" Barack

President Obama faces his final two years in office without one of his closest aides, Senior Adviser and White House Communications Director Dan Pfeiffer, who departed the White House last week.

The 39-year-old hit the campaign trail with then-Sen. Obama, D-Illinois in 2007. He talked with "CBS This Morning" co-host Charlie Rose about the impact of the presidency on Mr. Obama.

"He's been through a lot; he's had to make tough decisions," he said. "But at his core, the same genuine, good person, with the same faith and the goodness in the American people exists to me."

Mr. Obama was viewed during his campaign as a gifted leader, with the ability to move voters, to inspire them, but as president, he's been criticized for not communicating well enough, a shortcoming that Pfeiffer seemed to acknowledge.

"[I]n the first two years, I think we all stepped back and looked at it and realized that the trees had overwhelmed the forest. We were doing health care, we were doing save the auto industry, we were doing the stimulus and each one of those things were sort of their own thing and they didn't weave a broader narrative," Pfeiffer said. "But I think, on the issues the president cares about, public opinion has moved significantly in his direction over the course of our time in the White House."

There are few people who have served in the administration who have been closer to the president's decision-making process than Pfeiffer. It will come as no surprise that the president's approach, in Pfeiffer's words, is "deliberative" and "calm," with a touch of the devil's advocate.

"Sometimes you'll be in the room and you actually don't know what his position is because he is arguing the other side -- this is the law professor in him -- to test out the opposite argument, to see how strong it is," Pfeiffer said."It's a fascinating thing to watch his mind work as you sort of see him slowly work his mind around the problem from all the different sides."

And the president is generally comfortable with his decisions, whatever the outcome. "[He] very rarely ever looks, even if the decision goes poorly, spends a lot of time second guessing. He will try to learn the lessons from it," Pfeiffer said. "His belief is to try to do the right thing and let sort of let the chips fall where they may."

As for his own experience, Pfeiffer pointed out the extra gray hairs he's earned along with Mr. Obama over the years.

"There's photo evidence that we've all aged a lot in that period of time," Pfeiffer said. "I looked at a bunch of photos of myself from the early 2007 days and, one I can't believe how much I've aged, and I can't believe they hired a child basically to work on that campaign."

Pfeiffer said he'll miss most the "sense of camaraderie" at the White House.

"You know, I'm 39 and I probably have had the best job I'll ever have," Pfeiffer said. "Sometimes I wake up way earlier than I probably should and it takes me a minute or two to realize that this all actually happened because it seems impossible to imagine sometimes."