Sometimes everything is relative, and at other times relatives seem to be everything, at least when it comes to families of presidents and their desire to be with their kin. About to tell the world he was going to name his brother as his attorney general, John Kennedy told Ben Bradlee he planned to open his door at 2 in the morning, look down the street and if no one was there, whisper, "It's Bobby," and then close the door.

Two months later he named his brother-in-law Sargent Shiver to head the new Peace Corps, adding another number to the "buy one, get one free" slogan voiced by Bill Clinton years later, making it a three-for-one bargain matched only now when Donald Trump came to town, leaving his wife and youngest son back home in Manhattan, but with his son-in-law and his daughter in tow. There were complaints at the time but they turned out to be two of Kennedy's better appointments. That was partly because the "brother" part meant less than the fact that Bobby had been his campaign manager since the 1952 Senate race, and naming a campaign manager to a government position is a tradition as old as the hills. Fears that Bobby was too young and too rash to judge wisely came to an end in the Cuban Missile Crisis, when he crafted the "Trollope ploy" to answer a temperate earlier letter from Russia and ignore the bellicose one that came later, that showed the way out of a dangerous impasse. Motto: Nepotism isn't always the worst that can happen, and it certainly beat World War III.

Then came 1993, and Hillary Clinton, who fancied herself a "new kind of first lady," i.e. saw herself in fact as her husband's Robert F. Kennedy, insisted on control of his Health Care Reform Task Force, hailed at the time as a huge breakthrough act. "She has a larger number of senior officials assigned to her than the vice president," said Margaret Carlson. "Advisors often check with her before approaching the president...she has taken a place at the innermost circle of the White House and taken charge of the most far reaching social reform since the New Deal." What was wrong with this would be described only years later by Carl Bernstein in his book on the couple, "A Woman in Charge."

"Mostly, people thought the idea — the whole thing Hillary was setting up — was crazy," said Donna Shalala, citing her stubbornness, her intransigence, her combative nature, her sense of entitlement and her belief that she could not be wrong. Worst, she had gotten the job for the worst of all reasons: "I suspect that there was a level at which he knew it was a really dangerous idea," one deputy told him. "He was president in no small measure because she stood by him in the Gennifer Flowers mess...This was what she wanted, and he couldn't figure out how not to give it to her. And so he hoped for the best, and jumped [in]." In the next midterms, the Democrats lost both houses of Congress, and did't get the House back for more than a decade, something that never happened with Robert F. Kennedy.

Motto: Nepotism done really badly for all the wrong reasons is seldom if ever, your friend.

Now, it's Ivanka and Jared who want to be Robert F. Kennedy, for reasons of personal ballast, impulse control and domestic tranquility, so the Office of Family Matters will write a new chapter. But the question of whether nepotism works out well or poorly, as history tells us, depends on the nepots themselves.

Noemie Emery, a Washington Examiner columnist, is a contributing editor to The Weekly Standard and author of "Great Expectations: The Troubled Lives of Political Families."