WASHINGTON- Barack Obama has reached the stage of his presidency where if he wants to break out in song publicly, as he did with "Amazing Grace" in a eulogy on Friday, then he's going to do it.

With a year-and-a-half left in office, Obama is shedding some of his trademark "no drama" style for a looser approach, admitting that he feels more fearless and liberated.

It may also be in recognition that he has few big-ticket policy achievements left to enjoy in polarized Washington as the end of his two-term presidency approaches.

In a remarkable week for the president, a victory on Pacific Rim trade was snatched from the jaws of defeat on Capitol Hill on Wednesday. The Supreme Court on Thursday validated his signature healthcare law, guaranteeing he would accomplish a central second-term goal, to protect the 2010 Affordable Care Act from being dismantled by Republicans.

The icing on the cake came on Friday with the high court's decision to legalize same-sex marriage, a move Obama said was a "big step" toward equality for Americans.

After the court decision was announced, Obama took a Rose Garden victory lap.

"Progress on this journey often comes in small increments, sometimes two steps forward, one step back," he said.

"And then sometimes, there are days like this when that slow, steady effort is rewarded with justice that arrives like a thunderbolt."

Some Obama confidants described a more liberated, even feistier president, willing to mix it up with a heckler inside the White House, as he did on Wednesday. Or willing to use a racial epithet, long abandoned by civil society, to describe black people in urging more racial unity.

Why the change in style? He has more experience now, the president said in a podcast interview last week with comedian Marc Maron.

"Part of that fearlessness is because you've screwed up enough times that it's all happened. I've been through this, I've screwed up. I've been in the barrel tumbling down Niagara Falls and I emerged and I lived That's such a liberating feeling," he said.