There are moments so seared into our collective national memory that each of us can never forget where we were when we heard the news. So it was, for those of us who are old enough, with the assassination of President Kennedy. So it was with the fall of the Twin Towers on September 11, the date in our time that will live in infamy. And so it will be with the night we thought would never come — when American troops finally found and killed Osama bin Laden.

Here's my story. Three hundred of us were gathered outside a beach house in Santa Monica, Calif., at a memorial service for Kam Kuwata, a spectacularly gifted Democratic strategist, the maestro of the 2008 Obama convention in Denver, and an irreverent, remarkably decent human being who had died suddenly at the early age of 57. 

As Sen. Dianne Feinstein neared the conclusion of her powerful eulogy, she observed that as chairman of the Intelligence Committee, she was pretty good at keeping a secret. But she had one to share now — that Osama bin Laden had been killed. The news was as fitting as it was stunning; Kam was one of the supreme managers and consumers of news.

A sense of shattered disbelief and then elation tempered the sadness of that twilight, as Feinstein delivered what she said the president had just announced on television. (In fact, he hadn't yet — the speech was late. But CIA Director Leon Panetta had said she was free to speak about what she knew after 10:30 p.m. East Coast time.)

Kam's passing had been unthinkable; now as we marked it, something else unthinkable in a very different way had come to pass. It was a landmark moment for Americans, whether they were on a beach in Santa Monica or gathering at Ground Zero or in front of the White House. 

For the nation, the long-awaited outcome showed, as the president said, that we "can do whatever we set our minds to." It seemed to reaffirm the place in the world and the possibilities of an America that has increasingly yielded to self-doubt. 

There's no question too that the Obama presidency was renewed and transformed. 

The president has been criticized for not pounding his rhetorical chest or referring to the "global war on terror" in his talk. Republicans offered their praise, some of it no more than faint. Sarah Palin was one of those: She failed to mention Obama's name in her congratulations to the military on bin Laden’s elimination. The president she singled out for thanks was George W. Bush. It was preposterous, and most in the GOP, having the elementary intelligence to comprehend the scale of the event and the sweep of the national mood, were far more generous in their reaction. 

Republicans may want to return as swiftly as possible to the politics of Obama destruction, but that has become much harder — if not impossible. On the eve of big decisions about the debt ceiling and the budget, the president has new strength and credibility — and his Republican opponents and 2012 rivals have a stature gap that was always real but is now apparent.

The gap will only widen as the gripping insider story of the nine-month saga of the mission to get Osama is told and retold. Not since the 13 days of the Cuban Missile Crisis has there been a story of leadership equal to this in drama and appeal. The best sellers are already on the way.

And we already know how central and commanding the president's role was. He made the decision to wait as the intelligence was gathered and bin Laden assumed he was secure in his comfortable refuge. A hard call when the temptation had to be instant response. Obama rejected the option of a striking with bombs or drones; bin Laden might escape or his death could never be confirmed. A hard call because using American special operations forces risked both casualties and an equipment failure that could destroy the mission. The president had also decided not to inform the Pakistani government, precisely the call he had promised to make — and was assailed for proposing — during the 2008 campaign. Presumably Secretary of State Hillary Clinton, his critic then, did not dissent now.

The political effects of the operation will unfold over the months that lead to the next Election Day — and for years beyond it. The president's coolness and courage will also have a collateral effect, more starkly than ever confounding the racist emptiness of the "birthers" and the smearing of Obama as somehow sinister and un-American. Now more than ever, he is the president of the United States – and a commander in chief entirely worthy of the office and the trust that he holds.

The GOP can still contrive to reverse economic growth and job creation by forcing a default on the national debt or budget cuts too deep and too soon. But the president has the high ground and that kind of low politics will hurt the Republicans more than the recovery.

Moments engrained in American memory are matched by moments in the American presidency when great leaders set their mark on the office and indelibly define themselves – from FDR's First 100 Days to JFK's Missile Crisis to Ronald Reagan's gallantry after he was shot. I think we have just witnessed another such passage. 

And I think too of a happy warrior named Kam Kuwata, who believed that in the end, the good guys win. Despite the sorrow of the occasion, that night, on that beach in Santa Monica, it was suddenly more than possible to believe that he was right.