Liberal Democrats from the North haven't had much success in recent presidential elections — not Hubert Humphrey, not George McGovern, not Walter Mondale, not Mike Dukakis and not John Kerry. Democratic Southerners — Lyndon Johnson, Jimmy Carter and Bill Clinton — have done quite a bit better.

Sen. Barack Obama, of Illinois, knows this history. So why does he think he can be the first Northern liberal Democratic president since John F. Kennedy edged out Richard Nixon almost a half-century ago?

(1) There is no incumbent president or vice president running for the first time in more than 50 years. Add a controversial war, an unpopular incumbent and a shaky economy, and you have a wide-open race full of voters rethinking things as never before.

(2) As the first African-American candidate to seriously contend for either party's nomination, Mr. Obama offers Americans a sort of collective redemption at home and admiration abroad.

When Obama's wife, Michelle, said she had never been proud of America until her husband ran for office, she made explicit what seems to be the campaign's implicit contract: Vote for Mr. Obama and, at last, America, you can prove you are not a racist country and finally heal centuries-old wounds.

Many Americans are also tired of the flag-burning, embassy-storming and other virulent — and often violent — anti-Americanism broadcast into our homes from overseas. They apparently hope a young President Obama would recast the United States as a hip, likable multicultural society, marking an end to the stereotype of the U.S. as a stodgy white-guy superpower.

(3) Most important, Mr. Obama still continues to talk in platitudes of hope and change. His delivery is excellent and so far how he speaks rather than what he says is what has mesmerized crowds. Indeed, if Mr. Obama were honestly to articulate in any detail what he has stood for, his long laundry list of new taxes and social programs might not be so warmly received.

There is surely a reason why various monitoring groups have given Mr. Obama an almost-perfect liberal ranking based on his Senate votes.

He favors re-negotiating the North American Free Trade Agreement and threatening to raise some trade barriers, on the premise the United States cannot compete abroad — and that other countries won't follow suit and retaliate.

His version of the war on terror is largely a story of lost civil liberties and eroding the Constitution, not that we've done something right these past 6½ years to prevent another attack such as the one on September 11, 2001.

He has spoken of the surge as a failure —- not a success that has stabilized Iraq and paved the way for downsizing the U.S. troop presence there soon.

And he believes Iran has grown into a threat not just because of its desire to spread radical Islam, acquire the bomb, destabilize its neighbors and destroy Israel, but also largely due either to our presence in Iraq or to our diplomatic failure to talk and engage with President Mahmoud Ahmadinejad.

In a broader sense, the pessimistic Obama theme is that elites have stacked the deck against the average Joe, who can't get a doctor, pay for his children's college education or pay his mortgage. Therefore, we must take back more income from the better-paid and hire a lot more people in government like Barack Obama to more wisely administer the money.

Mr. Obama's overall message — to the extent we know from cross-examination and position papers — seems very different from Bill Clinton's, who reformed welfare, advocated free trade, held the line on government growth and spending, advocated strong international engagement, and emphasized crime fighting. Indeed, at home and abroad it's more reminiscent of George McGovern's hoped-for changes.

The irony is that Mr. Obama really does offer a change — not just in matters of youth, race and eloquence, but also in that we have not seen such a leftish philosophy on the national scene in over a generation.

His handlers should let Obama be Obama — in the way true believers once demanded that handlers stop sugarcoating Ronald Reagan and instead let him make the case for his bedrock conservative beliefs.

Mr. Obama should now follow through on his promises of a new politics of candor and transparency, and use his magnetism and persuasive skills to make the detailed liberal case for more taxes on the wealthier for more government services for the majority along with trade protectionism as the proper antidote to our problems.

Who knows? Maybe today's indebted Americans really do want to move leftward toward a centralized European model. But the voters should at least be given the chance to understand fully in 2008 what they may well get in 2009 and beyond.