1: Barack Obama

The great sociologist Max Weber described the power of charisma as "a certain quality of an individual personality, by virtue of which he is set apart from ordinary men and treated as endowed with supernatural, superhuman, or at least specifically exceptional powers or qualities." Some of Barack Obama's supporters have at times sounded as if they saw "the One" in these terms. His birth, background and eloquence, they believe, give him almost magical qualities. There's no doubt that Obama is intensely charismatic and that it provides him with unusual political capital. (Story continued below...)

But very soon—say on Jan. 20, 2009—his powers will start to mutate, and they will derive less from his persona and more from his office. He will shift, in Weber's terminology, from wielding charismatic authority to legal authority.

In January, Obama will gain the authority to run the government of the United States of America, and that is why he sits atop this list. No matter how charismatic, were he the president of Kenya, he would not be in this position (or, like the real president of Kenya, not even on this list). For all its problems, for all the battering it has taken, the United States remains the single most important country in the world—able to exercise influence in every realm and on every continent in a way that no other major power can. It remains, in the words of the German writer Josef Joffe, "the default superpower." Add to this Obama's special qualities, and the relief much of the rest of the world feels at seeing the end of the Bush administration, and you have a heady combination.

But presidents cannot simply remain charismatic symbols. They are forced to tackle the problems at hand, and their influence then grows— or ebbs—based on how they handle those challenges. However impressive they were as human beings, it was not in being but in doing that George Washington, Abraham Lincoln and Franklin Roosevelt built their enormous reputations. Whatever Obama may have thought when he began this journey, at a time when the war in Iraq was foremost in many voters' minds, whatever his campaign promises, his presidency will be judged on how he handles the economic crisis that now envelops the United States and the world. For Obama to be remembered as a great president, he has to do nothing less than rescue capitalism.

The first task is perhaps the most difficult: to restore confidence to Americans, and indeed to the world. While there has been much elation over Obama's election, there remains a deep pessimism across the country that is having adverse effects on the economy. People and corporations are still not doing much by way of buying, borrowing or lending —the heartbeats of modern capitalism. The political system has moved on to the automobile bailouts and the fiscal stimulus, but the original problem of trust in the financial system has still not been fixed. "Credit markets are still fundamentally broken," says David Swensen, chief investment officer of Yale University.