The economists have a term for it: opportunity cost - the benefits forgone when an investor puts his capital into one project rather than another. His choice may prove profitable, but another choice might have been even more so - and so he's lost the difference between the two. That's the opportunity cost, and it can be measured not just in dollars but in time or energy or anything else of value.

Politicians, like the rest of us, make much the same mistake when, given a chance to score political points, they seize the moment and exploit it for all it's worth, or rather for what they think it's worth. Actually they might gain something incalculably more by declining the opportunity to engage in a little cheap drama - and instead serve their fellow citizens by raising the level of public discourse, and win a place in history. That is true greatness.

There will always be those who think it's foolish to miss any opportunity to lambaste the opposition. Their philosophy: A soft word turneth away the voters. Every chance for a sound bite must be seized.

Let's hope there will also be those who try to rise above the fray to see farther, think more clearly and act more honorably.

It's the difference between a ring-tailed roarer like Howard Dean - the perpetual and now professional partisan - and a quiet thinker like Connecticut's Joe Lieberman, who's willing to speak unwelcome truths even to his own, inflamed party. And be willing to pay the price for it in a party primary.

It's the difference between a Joe McCarthy and an Adlai Stevenson. Let it be noted that Gov. Stevenson paid the usual price for thoughtfulness and eloquence in a televised age; he lost his race for the presidency in 1952.

(And in 1956, too, by which time he'd learned the cost of talking sense to the American people and was content to just repeat catch phrases, which availed him even less.) But in the presidential campaign of '52, he was still introducing novelties like reason and eloquence into, of all things, an American presidential race.

Some criticized Adlai Stevenson that year for "speaking over the heads of the American people" when he was only trying to get us to look up. Looking back, it's even clearer that one needn't have agreed with the gentleman from Illinois to admire his faith in the American people, and in the power of reason.

When a red-in-the-face Bill Clinton tells off an interviewer on Fox News, he may fire up his party's long frustrated base, and win the plaudits of those partisans who made up their minds long ago. About everything. But his little tizzy cost him more than his dignity. While reveling in the chance to tell off his critics, he lost an opportunity to raise the level of public discourse.

Amid all the finger-pointing rage and the kind of selective history that's good mainly for rhetorical purposes, reason evaporates. Bill Clinton's attack was followed predictably enough by counter-attacks, and what might have been a meaningful debate about the future gave way to one more rehash of the past. Given an opportunity to address the next generation, the former president seemed interested only in making points for the next election, or maybe the one after that. Which seemed the extent of his vision. Continued...