Politics makes strange bedfellows. Everyone knows that. This campaign makes for strange bed-hopping. (How post-modern.) Hillary haters find themselves cheering Sen. Ted Kennedy to rally Democrats behind Barack Obama. Some voters are seduced by Sen. Obama's inspiring rhetoric, but many others merely see him as a way to get the Clinton soap opera off prime time. (How post-everything.)

Cynicism is not the driving force of the campaign, but it is a force. The conventional Republican wisdom -- conventional wisdom is not always wrong -- is that Hillary would galvanize the wobbly conservatives who might stay home now that Fred Thompson is a drop-out. They might look at things differently if the race is finally between John McCain or Mitt Romney against Barack Obama.

Differences would be stark, and the debates could be enlightening. Experience and character should count for a lot. Whereas Hillary might say anything to get elected, Sen. Obama would be forced to move beyond inspiring rhetoric and get specific about his conventionally liberal positions on domestic and foreign policies. No triangulation for him. He could campaign on his authenticity, something she couldn't do. She still blames the vast right-wing conspiracy for her husband's infidelities.

Bill Clinton insists that Hillary and John McCain are close and they would make "the most civilized election in American history," but a McCain-Obama match might more readily live up to that interpretation. Civility is Mr. Obama's calling card, and John McCain continues to draw our admiration for his sustained courage and steely character in a North Vietnamese prison.

We all have our own ideas about who would make the best leader in these difficult times, but it's impossible to know exactly what kind of leadership a president will show in office before he actually moves into the White House. "Some men are born great, some achieve greatness, and some have greatness thrust upon them," Shakespeare observed in "Twelfth Night." This phrase rings with truth, but be aware that it comes from a letter written to deceive Malvolio, a clownish character who foolishly saw himself as being singled out for greatness.

Joseph Heller came close to another truth when he satirized the phrase in his novel "Catch 22": "Some men are born mediocre, some men achieve mediocrity and some men have mediocrity thrust upon them." Examples of greatness and mediocrity are sprinkled throughout the history of the presidency. Tacitus, the Roman historian, understood this frustration when he described a young Roman emperor who everyone thought was quite capable of ruling until he had to actually rule, and then he failed miserably. John F. Kennedy, more mythologized than actualized, died too young in office to enable us to take his full measure of competence. Camelot, after all, is a fairy tale.

Nothing seems to have so rankled Bill Clinton like Obama's remark that unlike Ronald Reagan, he was not a "transformational" president, the maker of sustaining changes in the way Americans see themselves. The angry behavior of the former president on the hustings for his wife underlines the point that luck and timing have powerful parts to play in forging successful leadership. Think Harry S. Truman. Had he not been chosen at the last minute to be FDR's running mate in 1944, he would have died as a decent, pragmatic man who became an ordinary senator to fade quickly into obscurity. Fortunately, and to the surprise of many of his contemporaries (and no doubt to himself as well), he rose to the stature of the office.

James K. Polk, the dark horse who defeated the dreams of Henry Clay to become the eleventh president, was the first president who was neither military hero nor elder statesman and rose far above public expectations to deal effectively with the challenges of his time. Most historians rank him in the top dozen presidents, for presiding over an enormous expansion of national territory including Texas, California, Oregon and other land west of the Rockies.

The rigor of presidential races is intensified in the relentless limelight of expanding media, making it difficult for the candidates to reveal who they really are, and making it difficult for us to measure them against myth and fiction. The limelight has bleached Bill Clinton of his blackness and darkened Barack Obama in his. The process has unearthed a long-buried animosity toward both Clintons. Bill and Hillary are not exactly strange political bedfellows, but it's difficult to see how they won't become estranged after the public mess they made in South Carolina. You could say, as the Bard might, that this marriage of true minds admits impediments.