Story highlights Obama -- known in his first term for his cool, detached style -- has been seen crying

The president's biographer attributes the shift to a new sense of freedom

In an emotional gun-control plea in his State of the Union, the chamber rose to its feet

Obama: "The one thing about being president is after four years, you get pretty humble"

President Barack Obama is showing his softer side. The man who was known in his first term for his cool, detached style has been crying, repeatedly.

It started the day after his re-election when a teary and happy president told campaign volunteers , "I'm so proud of you guys."

A month later he was overcome by grief as he wept openly in the White House briefing room after the Newtown, Connecticut, shootings. There were tears again during a heroes ceremony for Newtown victims, and while delivering remarks about Rev. Martin Luther King Jr.

Second-term Obama is not just showing his emotions, he's sharing them, too -- laughing with the Miami Heat at the White House and telling people in a Chicago audience that they're in the area where "Michelle and I fell in love."

The president's biographer attributes the shift to a new sense of freedom from winning a second term.

"I think we've all seen, actually since the day after his re-election a more relaxed Barack Obama, really something that took a lifetime for him to get to this point," David Maraniss said. "We've really seen a new Obama."

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The "new" Obama is venturing into territory the first term Obama shied away from.

He talked about his complicated biracial identity in this eulogy for Sen. Daniel Inouye of Hawaii.

"Here I was, a young boy with a white mom, a black father, raised in Indonesia and Hawaii," the president said at the National Cathedral in Washington. "And I was beginning to sense how fitting into the world might not be as simple as it might seem."

To kids at home in Chicago, he admitted he was often in trouble when he was a teenager.

"When I screwed up, the consequences weren't as high as when kids on the South Side screw up," he told them. "So I had more of a safety net but these guys are no different than me."

And, he used unusually personal language to describe King's struggles.

"We often think of him standing tall in front of these endless crowds, stirring the nation's conscience with a bellowing voice and a mighty dream. But I also thought of his doubts ... the lonely moments when he was left to confront the presence of long-festering injustice and undisguised hate," Obama told a crowd at the National Prayer Breakfast in February. "(I) imagined the darkness and the doubt that must have surrounded him when he was in that Birmingham jail, and the anger that surely rose up in him the night his house was bombed."

Obama's biographer says a more complete personality is coming into focus.

"I don't think one ever knows the real him. But I think that it's closer to being the private and the public Obama coming together in a clearer way," Maraniss said.

This warmer more revealing Obama was on display during the 2008 campaign. Then he used his biography to sell himself as the melting pot embodied.

His most vocal critics turned parts of his resume into punch lines, perhaps most memorably by former Alaska Gov. Sarah Palin at the 2008 Republican National Convention.

"I guess a small-town mayor is sort of like a community organizer, except you have actual responsibilities," Palin said.

Perhaps in reaction, once in office the president became more cautious about talking about his past. On most topics, he just didn't go there.

But now, free of the pressure to woo swing voters, he's back to using his story and his rhetorical skills to try to inspire audiences and pitch policies.

Obama himself said Tuesday night in Virginia: "I've run my last election."

He told CBS' Charlie Rose last summer that the biggest mistake of his first term was not communicating his vision with the American people.

"When I think about what we've done well and what we haven't done well, the mistake of my first term -- couple of years -- was thinking that this job was just about getting the policy right," he said.

"And that's important but the nature of this office is also to tell a story to the American people that gives them a sense of unity and purpose and optimism, especially during tough times."

These days he's hardly touchy-feely, but he's more likely to wear his heart on his sleeve. And use passion for political effect.

During the fight over forced spending cuts, he's made a clear effort to put faces on the impending changes. At one White House event, he got emotional as he stood in front of a group of first responders.

"And this is not an abstraction. There are people whose livelihoods are at stake. There are communities that are going to be impacted in a negative way," he said.

"And I know that sometimes all this squabbling in Washington seems very abstract, and in the abstract, people like the idea, there must be some spending we can cut, there must be some waste out there. There absolutely is. But this isn't the right way to do it."

Rewind back to four years ago in March 2009, the same president was confronted with a teacher about to lose her job. Instead of consoling her or expressing her concern, he asked if she got a "pink slip" and launched into his views on education policy.

These days he's doing better on the empathy test.

In a gun control plea at his recent State of the Union address , the chamber rose to its feet as a fervent Obama reminded the country of recent tragedies.

"Gabby Giffords deserves a vote. The families of Newtown deserve a vote," Obama said on the House floor.

"The families of Aurora deserve a vote. The families of Oak Creek and Tucson and Blacksburg and the countless other communities ripped open by gun violence, they deserve a simple vote."

That's the kind of emotional rallying cry he once saved for campaign style events outside the Beltway. No longer.

Even the president admits he has changed, in repeated humble brags.

"The fascinating thing about this job is the longer you're in it, the more humble you get and the more you recognize your own imperfections," he told House Democrats at their retreat in Virginia.

"The one thing about being president is after four years, you get pretty humble," Obama said Tuesday. "You think maybe you wouldn't but you become more humble. You realize what you don't know. You realize, you know, all the mistakes you make."

It's humility he can afford, after winning a second term.

"President Obama is never going to be the 'I feel your pain' Bill Clinton-type of president but he's getting closer," Maraniss said.