Every year since 1990, the Gallup poll has asked Americans to assess all the presidents since John F. Kennedy. And every year, Kennedy comes out on top.

Clinton's egregious act of self-indulgence was outdone by an impeachment based not on constitutionally required high crimes and misdemeanors but on a vindictive determination to bring down a president who had offended self-righteous moralists eager to put a different political agenda in place.

Lyndon Johnson is not a comfortable model for President Obama to imitate. He is an all-but-forgotten president - pilloried for the failed war in Vietnam and criticized for grandiose reforms conservatives denounce as the epitome of federal social engineering that costs too much and does too little.

Richard Nixon had a kind of Walter Mitty fantasy life. He was a man with a grandiose thoughts: dreams of not simply being president but maybe becoming one of the truly great presidents of American history.

Harry Truman wrote scathing letters, but he almost never sent them.

There is a line between scurrilous nonsense and serious discussion that laps over, especially in this day and age when you've got all this electronic media and these blogs and this kind of fanatical impulse to bring down the opposing candidate.

In counterfactual history, nothing is certain.

Dwight Eisenhower, the Republican nominee in 1952, made a strong public commitment to ending the war in Korea, where fighting had reached a stalemate.

The consequence of the Bay of Pigs failure wasn't an acceptance of Castro and his control of Cuba but, rather, a renewed determination to bring him down by stealth.

By the time a second term rolls around, the illusions about a president have largely evaporated.

To be sure, hunters and sportsmen back gun rights. Beyond that, there are millions who see guns as a defense against fear - fear of criminals breaking into their homes or assaulting them on city streets.

The Bay of Pigs was an operation the United States endorsed. That was a preventive operation. We were afraid that Castro was going to subvert the hemisphere.

Television has an awful lot to do with the Kennedy mystique and the fact that he's frozen in people's minds at the age of 46, and he was handsome and personable and witty and charming.

At the end of the day, Americans are not so keen on ideologues, people who have such fixed positions that they can't see any virtue in the other side's point of view.

Compared with other recent presidents whose stumbles and failures have assaulted the national self-esteem, memories of Kennedy continue to give the country faith that its better days are ahead. That's been reason enough to discount his limitations and remain enamored of his presidential performance.

In the late 19th century, the Populists - a protest movement of mainly disaffected farmers and workers - threatened to overturn established authority.

One doesn't simply write about Lyndon Johnson. You get the Johnson treatment from beyond the grave - arm around you, nose to nose. I should admit that he also reminds me of my father, quite an overbearing and narcissistic character. And in some ways, he reminds me of myself. Another workaholic.

What did in the Soviet Union was the Soviet Union.

After one party loses two elections in a row, there's sort of blood in the water.

To be sure, Kennedy did not discount the importance of words in rallying the nation to meet its foreign and domestic challenges. Winston Churchill's powerful exhortations during World War II set a standard he had long admired. Kennedy was hardly unmindful of how important a great inaugural address could be.

Vice President Biden's surprising declaration of unqualified support for gay marriage seems to have forced President Obama into a public endorsement of a controversial social issue. It is difficult not to suspect that Biden's pronouncement aimed to give the president some political cover.

Joseph McCarthy and the John Birch Society launched an anti-Communist crusade that won the support of millions of Americans in the 1950s.

Public scandals are America's favorite parlor sport. Learning about the flaws and misdeeds of the rich and famous seems to satisfy our egalitarian yearnings.

Allegations that President Clinton pardoned Marc Rich partly in return for donations to his presidential library have raised questions about the value of such institutions and the federal appropriations that support them.