It’s almost a staple of American public life: the big brother who is embarrassed by the antics of the overshadowed little brother.

Richard Nixon’s unsuccessful run for president in 1960, and his disastrous campaign for governor of California in 1962, were shadowed by disclosures that Nixon’s younger brother, Donald Nixon, had borrowed money from aviator-moviemaker-billionaire eccentric Howard Hughes in a failed bid to keep his drive-in restaurant from going under.

Flash forward to the days when Lyndon B. Johnson was president, and the Secret Service had to keep a close eye on his younger brother, Sam Houston Johnson, who liked to drink and talk too much. And recall President Jimmy Carter, whose little brother, Billy Carter, started a beer brand named after himself, then tried his hand at lobbying for Libya.

And now we have the story of  Preet Bharara, the U.S. Attorney for the Southern District of New York, and his kid brother, Vinit Bharara, as related recently ^[1] on The New York Times’ Dealbook. (Wait! Don’t go there yet! If you do, our punchline will be deflated.)

Last week, in a talk to the New York Financial Writers Association, Prosecutor Preet tried to knock down any notion that he is anti-business, just because he’s going after insider trading on Wall Street.  He also strolled down Memory Lane, noting that for a while they traveled similar paths.

Preet, now 42, graduated from Harvard, while Vinnie, three years younger, graduated from another Ivy League institution, the University of Pennsylvania. Each got a law degree from Columbia. Each worked at a big law firm for a time, then for a smaller firm.

“At that point, our paths diverged a little bit,” Preet Bharara related.” I continued to practice law, my brother decided to, with his best friend from high school, and grammar school, start a small internet company.  Because he was my brother, I gave him a little bit of money in that internet company. It didn’t do so well , I lost that money.”

Vinnie Bharara still landed on his feet, more or less, as his little start-up, an on-line sports card exchange, was bought up by Topps, where he served as general counsel for a while. Meanwhile, Big Brother Preet became a prosecutor in Manhattan, an aide to Sen. Charles E. Schumer (D-N.Y.), and eventually the U.S. Attorney.

But poor Vinnie had been bitten by the entrepreneurial bug.  Around the time that Preet was becoming the Scourge of Wall Street, Vinnie and a friend decided to take all their savings and embark on another internet venture — selling diapers, of all things. What were they thinking?

“I said, knock yourself out, let me know how it goes,” Preet Bharara recalled.

And how did it go? Well,  It seems that babies will never stop doing what they do, and Baby  Brother ’s baby business did all right. It was bought recently by Amazon.com for $540 million.

Aruna Viswanatha contributed to this story.