Three presidents and a wanna-be president are in our faces.

Ronald Reagan had an amazing week of tribute; Bill Clinton spends this week and the foreseeable future — alas — talking; George W. Bush has next week's Iraqi transition and John Kerry spends endless weeks traipsing and campaigning.

What can we learn about leadership from all this presidential timber crackling about?

When pitching his mega-book, Bill Clinton has stayed true to form. It’s all about him.

Clinton’s presidency was “all about me.” His book title, “My Life,” is thus apt. Reviews of the memoir commonly lead with the Monica Lewinsky (search) scandal. Then, near bottom of the review, comes the compulsory policy stuff. It’s also apt that Clinton’s on the personal-confessional “Oprah” before the policy-intellectual “Book Notes” of C-Span.

Reagan was the polar opposite. Rather than seeking office to be someone, Reagan accepted office to do something. In his fifties, Reagan was reluctant to enter politics. In his teens, Clinton began in politics.

When defeated for re-election as Arkansas governor, Clinton went around the state asking, “What did I do wrong?” His return to the statehouse next 'round was his first incarnation as “the comeback kid.”

When Reagan was defeated as a first-time presidential candidate — in 1976, edged out by President Ford at the GOP national convention — he held a news conference. Recently watching a rerun of that, I was stunned. The ever-sunny Reagan was downcast — as if he really expected to have toppled a sitting Republican president for the Republican presidential nomination.

Yet more stunning was Reagan's handling of the defeat. He talked about “the cause” — how to advance his anti-tax, anti-communism, anti-big government agenda.

He never went into confessionals. No “what I did wrong.” No personal plans. Refusing to say anything about himself, he asserted that “the cause” must go on.

What “cause” had Clinton? What ideas of government, besides getting himself into it?

No big idea that Clinton took into government — like health care reform — did he accomplish in government. He did have policy triumphs, some even historic contributions — welfare reform, free trade legislation and balancing the budget. But this policy trifecta came after the revolutionary Republican sweep of 1994, and flowed from that revolutionary band, not Clinton.

Reagan’s presidency was momentous with gigantic leaps of history. Clinton’s presidency was tumultuous with baby steps on his own policy.

Reagan was conventional in personal life, so much so as to be dismissed as boring by his first wife when seeking a divorce. But Reagan was daring in his policy pursuits.

Clinton, in contrast, was reckless in his personal life, but surprisingly risk-adverse in policy realms.

How does today’s presidential timber stack up?

Bush began as a downsized Clinton. He ran for president to be someone — like his dad — rather than to do something. Bush’s 2000 campaign was conventional, with him spouting the usual smattering of GOP schemes.

No one can recall anything Bush said during the three deadening debates. We only remember Al Gore’s heaves and eye-rolls.

But Bush had an “a-ha” moment, right after Sept. 11. His Reaganesque cause appeared. He would combat terrorism, with all his might.

Few others in office then would have given the go-ahead against Iraq as part of this cause-oriented presidency. How this mega-decision will turn out is up in the air. If disastrously — as Iraq has been going — then Clinton’s baby-steps will seem much preferable. If it turns out well, as could happen, then Reagan’s giant leaps will seem replicated.

How about Kerry?

Now, he sure seems minimalist. Kerry is running a blurry campaign for better government, posing as an anybody-but-Bush.

Kerry has all the markings of a transactional leader, none of a transformational leader.

But it’s quite early in the race. It may be early in his historic role. So it’s fitting that he, alone among the four, still defies clear definition as a leader.

Ken Adelman was a U.N. ambassador and arms-control director in the 1980s, accompanying President Reagan on his superpower summits with Mikhail Gorbachev. He now serves on the Defense Policy Board, and co-hosts www.TechCentralStation.com.