It was not just an endorsement, it was a rebuke.
Ted Kennedy didn't just back Barack Obama for president Monday.
Kennedy reprimanded Bill and Hillary Clinton and criticized the campaign they have been running.
"When so many others were silent or simply went along, from the beginning, he opposed the war in Iraq," Kennedy said of Obama.
Kennedy then thundered: "And let no one deny that truth!"
No one like Bill Clinton, who recently dismissed Obama's opposition to the war as "the biggest fairy tale I've ever seen."
And Kennedy was almost certainly talking about the Clintons when he said: "With Barack Obama, we will turn the page on the old politics of misrepresentation and distortion."
He added: "He is a fighter who cares passionately about the causes he believes in, without demonizing those who hold a different view."
And just to rub things in a little, Kennedy went so far as to appropriate Hillary Clinton's signature line and apply it to Obama.
"I know that he's ready to be president on ... day ... one!" Kennedy said.
A source close to Kennedy told me that, more than a year ago, Obama had gone to Kennedy and asked if he should run for president.
"Yes," Kennedy told him. "You don't get more than one chance at the brass ring, and this is your chance."
Kennedy was only 47, only a year older than Obama is now, when he announced for the presidency in November 1979.
But when Kennedy lost to Jimmy Carter, he never got another chance.
Kennedy also told Obama he expected to stay out of the Democratic primaries and not endorse.
He had too many friends running, Kennedy said, including Hillary Clinton and Chris Dodd.
But after Iowa, Kennedy began to reconsider and not just because Obama won there.
"He saw that Obama was bringing all branches of the party together," the source close to Kennedy said.
"Sen. Kennedy saw something on the faces of the people at the rallies that he had not seen in generations. Kennedy began to see Obama as a transformational figure."
He was not the first Kennedy to do so.
Back in 2005, Obama spoke at the Robert F. Kennedy Human Rights Award Ceremony, and afterward, Robert Kennedy's widow, Ethel, publicly called Obama "our next president" and said, "I think he feels it. He feels it just like Bobby did."
On Sunday, Caroline Kennedy wrote an op-ed article for The New York Times with the magical headline, "A President Like My Father."
"Sen. Obama is running a dignified and honest campaign," Kennedy wrote, again inviting comparison to the campaign of the Clintons.
"I have never had a president who inspired me the way people tell me that my father inspired them. But for the first time, I believe I have found the man who could be that president not just for me but for a new generation of Americans."
The generational theme is one that Ted Kennedy also hit hard during his endorsement speech at American University on Monday afternoon.
He used the word "young" eight times.
To win the nomination, Obama must put together a coalition of the young, minorities and the most progressive voters in the party.
And Kennedy will soon travel to New Mexico, Arizona and California to rally that support.
He has had some experience at this.
In 2004, Kennedy endorsed John Kerry and stumped across Iowa, tieless and coatless, laughing and joking, exuding wit and charm.
"I don't think about the presidency any more," Kennedy would tell the crowds. "Of course, I don't think about it any less."
Hillary Clinton may go on to win the Democratic nomination.
But if she does not, she will, to a certain extent, become Ted Kennedy: a person for whom the presidency is perpetually out of reach.