Leadership is a quality that everyone can recognise but a whole suite of academic debate has emerged over its definition.
For an example check out these Q&As from the NZ Leadership institute.
Here, between the leaders of our two major parties we see the positioning between the experienced Helen Clark, and the untested John Key (and many would argue Bill English is the real leader behind the scenes).
This opinion piece from The New York Times discusses how the requirements of leadership changes according to context & between Clinton and Obama:
Hillary Clinton has been a much better senator than Barack Obama. She has been a serious, substantive lawmaker who has worked effectively across party lines. Obama has some accomplishments under his belt, but many of his colleagues believe that he has not bothered to master the intricacies of legislation or the maze of Senate rules. He talks about independence, but he has never quite bucked liberal orthodoxy or party discipline.
If Clinton were running against Obama for Senate, it would be easy to choose between them.
But they are running for president, and the presidency requires a different set of qualities. Presidents are buffeted by sycophancy, criticism and betrayal. They must improvise amid a thousand fluid crises. They’re isolated and also exposed, puffed up on the outside and hollowed out within. With the presidency, character and self-knowledge matter more than even experience. There are reasons to think that, among Democrats, Obama is better prepared for this madness.