What makes a leader?
We examine this year's leading presidential candidates through that prism.
Our leadership categories are adapted from standards developed by Fred Greenstein, a Princeton scholar and author of "The Presidential Difference."
Greenstein says the modern presidency is so powerful, voters should take careful stock of the strengths and weaknesses candidates might bring to the job — from their psychology, emotional maturity and vision to the way they process information, manage and communicate.
Using Greenstein's work as a jumping-off point, we assess candidates in the following areas: political skills, communication skills, policy vision, decision-making style and management skills.
The eight profiled candidates have double-digit support in the latest national USA TODAY/Gallup Poll.
Sen. Barack Obama, D-Ill., learned grass-roots political organizing in Chicago, as both a civil rights lawyer and director of the Developing Communities Project, which worked with the poor and families whose breadwinners had lost jobs in the declining steel industry. He also served as a state senator from 1997 to 2004, where he earned a reputation for bipartisanship.
In his biography, "Obama: From Promise to Power," David Mendell portrays Obama as committed to making a difference, occasionally cocky and thin-skinned in private, and a man in a hurry.
To the man who introduced him to organizing and grass-roots politics in Chicago's tough South Side in the mid-1980s, Obama "was extremely idealistic."
Says veteran Chicago organizer Jerry Kellman: "He identified very much with those who were on the outside of things."
Obama's idealism soon met street reality, and some viewed him as an interloper lacking in the authentic experiences of the poor he represented. He upset some leaders in Chicago's black community by challenging or confronting established leaders. That included a 2000 primary challenge of Rep. Bobby Rush, D-Ill., which Obama lost badly.
Kellman said in a Dec. 4 interview that as a community organizer, "Barack was effective, and people who had something to protect in terms of turf, in terms of an established power base, would look for ways to discredit him. And the best way to discredit him was to portray him as an outsider."
But both Kellman and Mendell describe an Obama who eventually became more pragmatic, more accepted and, in 2004, triumphant in one of the most effective first steps on the national stage in American political history.
Obama became a protege and key ally of Illinois Senate President Emil Jones.
In a Nov. 16 interview with Gannett News Service, Jones described the young Obama as a "very effective legislator" who gathered bipartisan support for legislation "by working with legislators and getting to know them and not being dogmatic in debate, even though their views may have been different."
Jones saw similar political instincts when Obama said in a debate in July that he would be willing to meet with the leaders of Iran, North Korea, Syria, Cuba and Venezuela.
Obama's critics, most notably Sen. Hillary Rodham Clinton, D-N.Y., called his answer naive. The implication: that Obama's grandiose "let's talk it out" vision might end up with him caving in to or being used for propaganda purposes by enemies of the United States.
"I am not afraid of losing a propaganda battle with some petty dictator," Obama told a University of Virginia audience in October.