Last week, Rep. Joseph P. Kennedy III became the first Kennedy to lose an election in Massachusetts.

I don’t have anything against Rep. Kennedy. By many accounts he was a good congressman and a reasonably humble fellow, willing to listen and learn.

But it’s great to see a dynasty thwarted.

This Kennedy, of course, is the son of Joseph P. Kennedy II, who also served in the House. His grandfather, Robert F. Kennedy, served as U.S. senator from New York. His grandfather’s brothers were President John F. Kennedy and Sen. Edward M. Kennedy. His cousins include Patrick Kennedy, Ted’s son, who served in the House, and former Ambassador to Japan Caroline Kennedy.

Some people love that family history. I don’t.

It’s always seemed odd that the United States — a country that fought a revolution to free itself from the rule of hereditary kings — is so enamored of political dynasties. Though we talk a good game about meritocracy, and most of us would strenuously object to nepotism on principle, we’ve voted to keep power within certain families since the earliest days of the republic.

It goes back, obviously, to the early 1800s, when John Quincy Adams followed his father into the presidency. But there are also the Roosevelts — including but not limited to Teddy and FDR, the Longs in Louisiana, the Bushes (beginning with George H.W.’s father, Sen. Prescott Bush), the Rockefellers, the Udalls (mostly in the Southwestern U.S.), the Tafts, the Cuomos, pere et fils. At the state level, there are many, many other such families across the country.

According to the economist Seth Stephens-Davidowitz (doing what sounded a bit like a back-of-the-envelope estimation in 2015), the son of a governor has about 6,000 times better chance of becoming a governor than the average American. The son of a senator has about an 8,500 times higher chance of becoming a senator.

Sure, sometimes a governor’s son or daughter is the best person for the job. But I don’t think we want to be a country where power is passed so routinely from generation to generation within the same family just because they seem safe or familiar or because we recognize the name. (For the record, the longest-existing dynasty in the world today is the Yamoto family, which has been the imperial family of Japan for at least 1,500 years.)

And speaking of dynasties, was I the only one who got a cold chill watching Donald Jr. and Ivanka at last week’s Republican convention? Maybe I’m wrong, but I saw something in their demeanors that screamed out: “You haven’t seen the last of us.”

Obviously, any American is entitled to run for office, regardless of what his or her parents did for a living. And some of the younger members of dynastic families have brought a lot to the job, in part because they grew up — like Jerry Brown and Andrew Cuomo — watching their parents govern.

Furthermore, it’s common enough in all sorts of fields for children to follow their successful parents into the family trade. Just ask Michael Douglas or Angelina Jolie.

But in a democracy, it feels somehow unhealthy that just because a candidate for office has a particular name and a particular pedigree, voters think they know what they stand for and how they’ll do at the job. It seems unfair that name-brand novices should waltz in with such unearned advantages. And even more important, voters do themselves a disservice when they jump to conclusions like that.

In 2011, Boston-based pollster Steve Koczela asked Massachusetts voters for their opinion of a fake Kennedy — a “Matthew Kennedy” who had never actually existed in the Massachusetts political world. With no further information, according to Koczela, 25% of voters surveyed said they had a favorable opinion of him. Only 1% had an unfavorable impression.

That’s the advantage of the name.

I had a thoughtful conversation recently with Hamilton Fish — the fifth Hamilton Fish in his line — whose father was a moderate Republican congressman and whose grandfather was a right-wing Republican congressman and whose great-great grandfather was a senator and governor of New York as well as U.S. secretary of State. In 1988, the younger Hamilton ran for Congress near the family’s old district as a liberal Democrat, and lost by a few hundred votes.

“I was born with a fantastic name — a golden name,” he says now. “There was no money attached to it, so I didn’t have the resources to easily leverage the advantages of dynasty the way many have. But I regarded my name as my inheritance and I tried to put the name to use in service of the values I believed in.”

OK, that’s not the worst thing in the world. By all means, those born with privilege — or with a good, marketable name — should do what they can to make the world a better place.

But voters should beware. Don’t buy the new model based on the old model.

And for the record, I’m not looking forward to the prospect of future matchups between Donald Jr., Eric, Ivanka, Chelsea, Malia and Sasha.

(Nicholas Goldberg is an associate editor and op-ed columnist for the Los Angeles Times.)