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.

William Henry Harrison, who died of pneumonia in April of 1841, after only one month in office, was the first Chief Executive to hide his physical frailties.

Truman is now seen as a near-great president because he put in place the containment doctrine boosted by the Truman Doctrine and the Marshall Plan and NATO, which historians now see as having been at the center of American success in the cold war.

Whatever the long-term legal prospects for same-sex marriage, President Obama's willingness to put the matter front and center in an election year can at least make him a candidate for inclusion in Kennedy's Profiles in Courage.

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

Racial segregation in the South not only separated the races, but it separated the South from the rest of the country.

The greatest presidents have been those who demonstrated astute judgment in times of crisis - often despite the advice they were getting.

President Obama can talk about having no grand schemes and making no big gains, but the reality is he can't get anything of significance through Congress.

For style and for creating a mood of optimism and hope - Kennedy on that count is as effective as any president the country has had in its history.

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.

Nixon did not anticipate the extent to which Kissinger, whom he barely knew when he appointed him national-security adviser in 1969, would be envious and high-strung - a maintenance project of the first order.

Presidential aspirants reach for the highest office to satisfy some yearning for greatness or even immortality.

Despite an unqualified understanding that U.S. national security was inextricably bound up with Britain's survival, F.D.R. knew that his reelection in part rested on the hope that he would keep the country out of war.

What makes war interesting for Americans is that we don't fight war on our soil, we don't have direct experience of it, so there's an openness about the meanings we give to it.

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.

Nowadays, everyone seems to have a blog that finds readers.

It's always valuable for someone running for president... to have as much bipartisan support as possible.

Theodore Roosevelt had drawn public attention to his attractive family in order to create a bond with ordinary Americans. Eleanor Roosevelt had successfully broached the idea that a First Lady could be nearly as much a public figure as her husband.

The Bay of Pigs is one of America's most infamous Cold War blunders, and it has been studied, debated, and dramatized endlessly ever since.

The lifelong health problems of John F. Kennedy constitute one of the best-kept secrets of recent U.S. history - no surprise, because if the extent of those problems had been revealed while he was alive, his presidential ambitions would likely have been dashed.

In counterfactual history, nothing is certain.

Like Lyndon Johnson, President Obama understands that timidity in a time of troubles is a prescription for failure.

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

Success in past U.S. conflicts has not been strictly the result of military leadership but rather the judgment of the president in choosing generals and setting broad strategy.

The Cold War is over. The kind of authority that the presidents asserted during the Cold War has now been diminished.

Flattery was one of Kissinger's principal tools in winning over Nixon, and a tool he employed shamelessly.

Eisenhower was quite supportive of Kennedy and Johnson in terms of foreign policy.

A presidential candidate's great desire is to be seen as pragmatic, and they hope their maneuvering and shifting will be seen in pursuit of some higher purpose. It doesn't mean they are utterly insincere.

I think the most important thing that comes out of the meeting between Churchill and Roosevelt in early 1942 is a commitment on Roosevelt's part to fight Europe first. To struggle first against Germany and put Japan and the Pacific as a secondary theatre in the conflict. And this is what Churchill was after.

In 1800, in the first interparty contest, the Federalists warned that presidential candidate Thomas Jefferson, because of his sympathy expressed at the outset of the French Revolution, was 'the son of a half-breed Indian squaw' who would put opponents under the guillotine.

How many State of the Union addresses do people remember? They don't resonate that way.

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.

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

When President Obama first unveiled his gun control proposals recommending a ban on assault weapons and high-capacity magazines and better background checks, there seemed to be momentum behind the effort. But then the proposals ran into a wall.

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

Few American presidents are held in higher esteem than Thomas Jefferson. Though historians have scrutinized every phase of his long public career and found him wanting in a number of respects, he holds an unshakable place in the pantheon of American heroes.

Historians evaluating George W. Bush's first term will focus on foreign policy and, most of all, 9/11. I think they will criticize him for his early reaction, for not returning at once to Washington, D.C.

The Atlantic conference in the North Atlantic off Newfoundland is a dramatic moment in World War II history because for the first time, Roosevelt and Churchill are meeting face to face in this war.

Despite all the public hand-wringing about negative advertising, political veterans will tell you that it persists because, more often than not, it works. But tearing down the other guy has another attraction: It can be a substitute for building much of a case for what the mudslinger will do once in office.

Henry Kissinger never wanted the 20,000 pages of his telephone transcripts made public - not while he was alive, at any rate.

I think experience is a terribly overrated idea when it comes to thinking about who should become president.

When Gingrich attacked CNN's John King for bringing up his alleged proposal of an open marriage to his second wife, Gingrich accused him of lowering the level of discourse in a presidential debate, suggesting that such a discussion is unworthy of consideration by voters.

The disaster at the Bay of Pigs intensified Kennedy's doubts about listening to advisers from the CIA, the Pentagon, or the State Department who had misled him or allowed him to accept lousy advice.

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.

In seeking an empire of liberty, Jefferson wished not only to expand the country's territorial holdings, but also to extend American institutions around the globe.

Experience helped Richard Nixon, but it didn't save him, and it certainly wasn't a blanket endorsement. He blundered terribly in dealing with Vietnam.

Despite its flaws, the American electoral system has produced Lincoln, the two Roosevelts, and Harry Truman.

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.

Some Kennedy aides have always insisted that Johnson misread J.F.K.'s plans for Vietnam. They say that Kennedy had begun to rethink the U.S. presence in Indochina and was reluctant to increase it.