Vernon Jordan -- Clinton's best friend and my personal mentor

Vernon Jordan attends the 40th Anniversary Gala for "A Mind Is A Terrible Thing To Waste" Campaign on March 3, 2011 in New York City.

David Gergen has been a White House adviser to four presidents of both parties and is a senior political analyst at CNN. A graduate of Harvard Law School, he is a professor of public service at the Harvard Kennedy School and co-founded its Center for Public Leadership. The views expressed in this commentary belong to the author. View more opinion at CNN.

(CNN)Some years ago, on PBS News Hour, I interviewed the historian David Herbert Donald about his new biography of Abraham Lincoln. "What is the most important asset a president needs?" I asked. Without hesitation, he replied: "A friend."

David Gergen
He was right. The presidency, as he pointed out, can be a lonely place where its occupant isn't quite sure whom he (or someday she) can trust to give him unvarnished truth. His advisers may be afraid to level with him, especially when delivering bad news, or they may have unspoken agendas of their own.
    That's precisely why a president needs a close friend, someone whose discretion and independent judgment are both guaranteed. And, ideally, whose company is reviving.
      That analysis came instantly to mind on Tuesday with the death of Vernon Jordan, the civil rights leader and presidential adviser, at the age of 85. Through his roles in various civil rights organizations -- perhaps most notably as president of the National Urban League -- and beyond, Vernon established a renowned commitment to racial equality. I knew him best as the closest friend that President Bill Clinton had during his eight years in the White House -- and one who will long be missed.
        When Clinton and his first chief of staff, Mack McLarty, recruited me to join his White House team as a senior counselor five months into his presidency, I soon saw a pattern: Whenever disputes erupted among his advisers (as they did a lot in those early days), the best answer was always the same: "Let's call Vernon." He was practicing law a few blocks away and could arrive in the Oval Office while arguments were still raging. Vernon's counsel was always wise and served the President -- and those who worked for him -- well.
        He also became a quiet mentor to several of us White House staffers. When time permitted, the two of us would slip away for lunch at the F Street Club where he filled me in on the backstory of every political battle. Simply put, whatever use I had in advising Clinton depended heavily upon what I learned from Vernon.
          Shortly after I arrived, Vernon and I, along with our wives, attended a large dinner at the home of Ben Bradlee, the executive editor of the Washington Post. There I saw another reason why Clinton valued him. Midway through the meal, a young staff member delivered the same note to each of us: a White House aide from Arkansas, Vincent Foster, had suddenly died. Immediately, Vernon and I drove together to the Foster home. The President was already there, consoling his widow; and Clinton himself was devastated.
          When Clinton left, he asked Vernon and I to join him at the White House. Hillary Clinton, at the time, was in Arkansas and joined in by phone. I saw then how much comfort Vernon could provide to the President and the first lady in a time of crisis. He was a sympathetic, soothing presence and helped them to see that in the midst of their grief the best way to honor Vince was to keep trying to deliver their best -- day-in, day-out.
          Years later, after I left the White House, I could also see just how much Clinton might miss him when Vernon wasn't available. That became clear after the story broke about Clinton's relationship with Monica Lewinsky. No one in the world could have been better in giving sage advice at that moment than Vernon could.
            There was one big problem, however: the President's personal secretary had previously asked Vernon to find a job for Lewinsky, which he had done. With an investigation quickly starting up, lawyers advised both the President and Vernon that they shouldn't talk to each other. I cannot be sure about who the President ultimately took counsel from, but I have often wondered if Clinton would have come through the Lewinsky saga less beaten up had he been able to talk to his closest friend about navigating the political landscape.
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            Indeed, Vernon Jordan was one of the most charismatic and savvy men I have ever met. He ranks right up there with Clark Clifford, Bob Strauss, Bryce Harlow and Lloyd Cutler in the quality of their counseling of recent chief executives. And, for Bill Clinton, he will always be a president's best friend.