No one likes a political loser, especially when they are defeated in a presidential election. And no party seems to cast aside those who fail at the ballot box as quickly and as ruthlessly as the Democratic Party. After his ignominious defeat under a mountain of negative attacks in 1988, Michael Dukakis quickly became persona non grata among Democrats; after being defeated by George Bush in 2000, Al Gore wandered in the wilderness for years; and since losing in 2004, John Kerry has consistently and often unfairly taken abuse from all corners.

But last night, Mr. Kerry earned a healthy dose of political redemption delivering possibly the best non-acceptance speech at a Democratic convention since Mario Cuomo and Jesse Jackson wowed the crowd in San Francisco more than two decades ago. Mr. Kerry demonstrated a passion and intensity that he rarely showed on the campaign trail in 2004. In doing so, he not only brought the partisan crowd in Denver to a fever pitch, but he became the first Democratic politician in recent memory to so openly and courageously defend the often maligned patriotism of his party.

Mr. Kerry offered righteous indignation to the partisan crowd, as he excoriated George Bush and the Republican Party, particularly for its conduct of American foreign policy:

Never in modern history has an administration squandered American power so recklessly. Never has strategy been so replaced by ideology. Never has extremism so crowded out common sense and fundamental American values. Never has short-term partisan politics so depleted the strength of America’s bipartisan foreign policy.

But beyond attacking the Bush administration, Mr. Kerry provided voters with the most direct and sustained attack against John McCain heard this week in Denver. Even after praising Mr. McCain as a friend of 22 years, Mr. Kerry went after his colleague -- and a man who he supposedly offered the vice presidential slot to in 2004 -- in an unusually personal and stinging attack:

To those who still believe in the myth of a maverick instead of the reality of a politician, I say, let’s compare Senator McCain to candidate McCain. Candidate McCain now supports the wartime tax cuts that Senator McCain once denounced as immoral. Candidate McCain criticizes Senator McCain’s own climate change bill. Candidate McCain says he would now vote against the immigration bill that Senator McCain wrote. Are you kidding? Talk about being for it before you’re against it.

The Democrats in Denver have seemed resistant to go after John McCain’s changed positions on a number of key issues. John Kerry felt no such reticence on Wednesday night, and one can imagine that he took enormous satisfaction, and even revenge, in evoking the words that doomed his presidential bid four years ago.

Now, if Mr. Kerry had stopped there this would have been an effective partisan speech -- memorable in the moment but likely soon forgotten. But what John Kerry said at the end of his remarks took a very good speech into the pantheon of great speeches.

For more than two generations, one of the dominant narratives in American politics has been the notion of Democratic “weakness” on foreign policy. Democrats, the stereotype goes, do not love their country; they are not patriotic, they are as Jeane Kirkpatrick famously declared at the G.O.P. convention in 1984, blame America-firsters. And for years, Democrats have struggled to fight back; often choosing political artifice over impassioned persuasion. But, last night in Denver, John Kerry fought back:

How insulting to suggest that those who question the mission, question the troops. How pathetic to suggest that those who question a failed policy, doubt America itself. How desperate to tell the son of a single mother who chose community service over money and privilege that he doesn’t put America first.

Pathetic, insulting and desperate are not the words that Democrats frequently use on the campaign trail and particularly not in the context of national security. As for the idea that community service belongs in the same lexicon as military service … well that’s something you are even less likely to hear.

Nearly 56 years after Adlai Stevenson stirringly told the America Legion that “patriotism is not the fear of something; it is the love of something,” John Kerry took a similar approach, declaring: “Patriotism is not love of power or some cheap trick to win votes; patriotism is love of country.”

And instead of hiding behind showy displays of patriotic symbolism, Mr. Kerry offered a full-throated defense of the idea that dissent is as pure a form of patriotism as any that exists in a democratic society:

Years ago when we protested a war, people would weigh in against us saying, ‘My country right or wrong.’ Our answer? Absolutely, my country right or wrong. When right, keep it right. When wrong, make it right. Sometimes loving your country demands you must tell the truth to power.

Whether one is a Democrat or Republican, these are the types of words that need to be heard on the campaign trail. In recent years, the patriotism of Democratic candidates has been all too regularly questioned; and the very notion of dissent scoffed at by some as un-American. This is no way to have a debate about national security or, for that matter, elect a president, and John Kerry, who regularly saw his patriotism laid out for scrutiny, knows all too well the damage that such attacks can have on not only one’s political future but the national discourse.

His words last night were long overdue -- some Democrats would say four years overdue -- but better late than never. For John Kerry it was likely a bittersweet moment, but perhaps now Democrats will again embrace their past standard bearer.