ANALYSIS By RICK KLEIN @rickklein:

For President Obama, the hope is that the 50 th anniversary of the March on Washington marks a new start, if not quite a new dream.

In a day brimming with historical significance, the president reached to the past to frame the choices ahead. He started with the fading but still living history of Martin Luther King Jr., and no person alive could stand as the embodiment of King's famous dream better than the first African-American president.

More significantly, there's Obama's own political past - as the vessel through which so many Americans channeled their own hopes and expectations when he burst onto the scene.

The "promise of this nation will only be kept when we work together," Obama declared today, sounding very much like a candidate who wasn't seasoned by Washington realities. "We'll have to reignite the embers of empathy and fellow feeling, the coalition of conscience that found expression in this place 50 years ago."

In a tidy piece of historical significance, today marks both the 50 th anniversary of King's speech and the fifth anniversary of Obama's accepting the Democratic nomination for president. Obama's speech today recalled his moment in history perhaps more than it did King's.

That's because the lessons the president chose to draw from 50 years back were more than relevant in his own ascendance five years ago. Obama's hope is that they can become relevant again, even in a calcified, bitter political environment.

"The good news is, just as was true in 1963, we now have a choice. We can continue down our current path, in which the gears of this great democracy grind to a halt and our children accept a life of lower expectations; where politics is a zero-sum game where a few do very well while struggling families of every race fight over a shrinking economic pie," Obama said.

"Or we can have the courage to change. The March on Washington teaches us that we are not trapped by the mistakes of history, that we are masters of our fate."

The president made glancing mention of his political opponents, accusing them - though not by name, as he did not utter the words "Republican" or "Democrat" - of advancing a "great untruth, that government was somehow itself to blame for their growing economic insecurity." For populist, pulpit-ready effect, he dropped more than a few g's.

He framed the goals of those who marched a half-century ago as broader than civil rights, in a way that aligns with his own broad second-term agenda, now stalled in Congress. Those who marched with King weren't interested in "some abstract ideal," he lectured his crowd.

"They were there seeking jobs as well as justice. Not just the absence of oppression but the presence of economic opportunity," the president said.

Obama has 3 ½ years to work with, not 50. But just as King drew on Lincoln's legacy in making his case, Obama today reached back to King for inspiration he hopes carries over among those who were once so passionate about his own promise.

"No one can match King's brilliance, but the same flame that lit the heart of all who are willing to take a first step for justice, I know that flame remains," Obama said.

It will take far more than speeches - "just words," as Hillary Clinton's famously stinging critique of Obama had it - to break through the current logjam. President Obama, though, wants to start again where he began, linked to history, and full of hope.