It would be silly to make Caroline Kennedy the White House science adviser: She's not a scientist. It would be silly to name her fire commissioner of New York City: She has no background in public safety.
The standards are different in other fields. Kennedy has no previous known interest in Japan, Asia or international relations and is not a diplomat. But Barack Obama has chosen her to be the next ambassador to Japan.
Liz Cheney, likewise, is not inhibited by anything she lacks. She went to high school in northern Virginia, college in Colorado and law school in Chicago, before taking up residence in the Washington, D.C. area. Under George W. Bush, she held a couple of State Department jobs for which she had no obvious qualifications. But now she's running for the U.S. Senate from Wyoming.
You could pick a name out of the phone book and find someone with better credentials. But these names are not random. They are household names, made famous by their fathers: John F. Kennedy and Dick Cheney. So the daughters carry an aura of expertise and gravity.
They benefit from "branding" -- their association with the genuine accomplishments of famous relatives. But the logic behind that appeal only goes so far. Just because you wear Nike shoes doesn't mean you'd buy a can of Nike beans. A Cheney's virtues, if any, may not be present in another Cheney.
A family connection can give clues to the policies someone would pursue. If you elect someone whose last name is Paul, you don't expect a rabid left-winger. If you vote for a Udall, you can assume he or she won't pave over Yosemite.
But it reveals nothing about their abilities. George W. Bush didn't inherit his father's knowledge of international affairs, contacts with foreign leaders or aversion to marching on Baghdad. Jack Kennedy was considered somewhat intellectual, but nephews Joseph and Patrick showed up on lists of the dumbest members of Congress.
Caroline Kennedy has impressed people writing books, serving on boards and generally burnishing the family reputation -- something not all of her cousins have done. Cheney has established herself as a forceful advocate for the sort of conservative policies her father advanced. But if their names were Smith and Jones, they'd never be considered for these jobs.
What Kennedy will bring to Tokyo is celebrity and glamour, which the Japanese are said to value. What Cheney would bring to Congress is a caustic ideology straight out of Fox News, which may excite some Wyoming Republicans. You could almost forget that there are people who have spent years preparing to do the real work that goes with these jobs.