In passionate support for his successor and righteous anger for her opponent, in a voice we have rarely heard since those heady days of "Yes We Can," Barack Obama rallied to Hillary Clinton and took it to Donald Trump, Wednesday night, casting this election, not as a contest between Democrats against Republicans or progressives against conservatives, but good against evil. Nothing less.
The values of hope, of tolerance, of belief that things can and will get better if Americans work together rather than tear at each other "are still cherished by people of every party, every race, every faith," the President told thousands of ecstatic Democrats at the national convention in Philadelphia. "That's why everyone who threatens our values, whether fascists or communists or jihadists or home-grown demagogues will always fail in the end. That is America." He wasn't thinking of George Wallace or Huey Long.
Donald Trump has committed outrages never before witnessed in a presidential candidate – slandering Hispanics and Muslims, calling his Democratic opponent corrupt and, on Wednesday, inviting Vladimir Putin to hack Hillary Clinton's e-mails.
Wednesday night, Mr. Obama and his allies declared this would not stand.
One of the most powerful moments of the night may have belonged to Vice-President Joe Biden, who in measured tones, in a pin-drop-silent hall, offered a devastating indictment of "a man who embraces the tactics of our enemies: torture, religious intolerance. You all know, all the Republicans know, that's not who we are," which was all the more powerful for being said quietly, rather than loudly, from a position of confidence, not fear.
There was retired Admiral John Hudson, who brought up Mr. Trump's derision of Senator John McCain for being captured in Vietnam. "Donald, you are not fit to polish John McCain's boots."
And then there was former New York mayor Michael Bloomberg: "I'm a New Yorker, and I know a con when I see one."
Mr. Obama might have chosen to take the high road and let others sling the muck. He was not inclined to. Donald Trump angers this man.
"The Donald is not really a plans guy. He's not really a facts guy either," the President derided. "Does anyone really believe that a guy who spent his 70 years on this Earth showing no regard for working people is suddenly going to be your champion, your voice? If so you should vote for him."
But unlike Ronald Reagan, who barely mentioned George H.W. Bush when he asked Americans to give his successor another four years, Mr. Obama spent much of his speech praising Ms. Clinton, in particular her decades of experience as the wife of a governor, the wife of a president, a senator and a secretary of state.
"I can say with confidence, there has never been a man or a women – not me, not Bill, nobody, more qualified than Hillary Clinton to serve as President of the United States of America," he maintained. Ms. Clinton joined him onstage at the end, their wars for the nomination in 2008 long behind them.
Mr. Obama spoke as well about his own accomplishments as president: righting an economy on the brink of depression; bringing millions of the uninsured into the health-care system; fighting to protect the environment.
Not everything he wanted to achieve came to pass, but Mr. Obama made it clear that he saw in Ms. Clinton someone who would preserve his legacy and advance his agenda, as well as her own.
He was at his best, though, when he defended his vision of America, an America that was reconciling – albeit imperfectly – its internal contradictions, where a marine could celebrate the husband he loved, where a women could succeed an African-American as president.
"The American dream is something no wall will ever contain," he declared, in a parting shot at the reality-TV star who would presume to succeed him.
"What I have seen more than anything is what is right with America."
If Donald Trump believes this righteously angry president and his legacy can be easily and derisively dismissed, he's in for a surprise.