Since Congress began meeting in 1789, 400 parent-child duos have served in the House and Senate, along with 190 pairs of siblings, according to data compiled by House and Senate historians. The percentage of "legacy lawmakers" reached its highest point in 1848, when more than 16% of Congress had been preceded in office by a relative, according to Pedro Dal Bo, a Brown University economist who co-authored a paper last year on American political dynasties.
The numbers have declined since, but the kinship caucus in the current Congress is substantial: 22 House members and five senators are children of former members of Congress.
The advantages of family connections are obvious in some of this year's campaigns.
Ben Quayle's $1.1 million in contributions make him the top fundraiser among 10 candidates vying in the Aug. 24 primary for the GOP nomination in a suburban Phoenix congressional district. His donors include prominent associates of his father, Dan. How many other political novices could get former Defense secretary Donald Rumsfeld to write a check for $1,000?
Besides Quayle, so did Chris Nixon Cox, a Republican running for Congress and grandson of the nation's 37th president. "He was a great grandfather," Cox says of Richard Nixon. "He used to take us out for trick or treat."
Cox, whose father, Ed, is New York's GOP chairman, doesn't mind using his middle name in campaign literature but says there's a flip side to the notoriety.
"I have to earn this," he says of his campaign for a Long Island House seat. "There's no such thing as a dynasty."
A familiar last name can force candidates to work harder to prove themselves, says New York Assemblyman Adam Clayton Powell IV.
"I could make subways and buses run free and there are still some people who would say, 'Oh, that's just Adam Clayton Powell's son.' In that sense, it's hard to carve out your own identity," says Powell, a son of a legendary congressman.
Powell is trying to defeat veteran Rep. Charles Rangel, D-N.Y., in a Sept. 14 primary that has turned into an intergenerational grudge match.
Rangel, who is facing 13 ethics charges in the House for failure to report income and assets, not paying taxes and his use of a rent-subsidized apartment, defeated Powell's father 40 years ago for the Harlem congressional seat.
Both Missouri Senate candidates bristle slightly when asked whether they'll benefit from their families' electoral successes.
"This election is going to be about Rep. Blunt and me," Carnahan says. "I've got a record in my office as secretary of State of standing up for consumers." Blunt notes that he won his first county office several years before his father, Leroy, went to the state Legislature. "I was the first Blunt elected to anything, as far as we know," the congressman says.
The mixed feelings political progeny have about their powerful and, sometimes, polarizing names is reflected in the ways they play out in their campaigns.
"Rory" reads Democratic nominee Rory Reid's campaign posters in the Nevada governor's race, playing down the last name he shares with Senate Majority Leader Harry Reid, who is facing a highly competitive race for re-election. The younger Reid's campaign declined an interview request about how he's handling his family ties.