‘You Are My Brother’
For all of that, Mr. Obama grew genuinely fond of his vice president, learning to appreciate Mr. Biden’s authenticity and embrace his contrary voice.
“You know what has surprised me?” Mr. Obama said at one of their lunches. “How we have become such good friends.”
“Surprised you?” Mr. Biden joked.
“Both of them came to understand that neither was going to change,” Mr. Rhodes said in an interview. “Obama came to understand that Biden was going to speak his mind and sometimes he was going to say things that weren’t on the script. That’s both his strength and his vulnerability, but you take someone for who they are.”
“And Biden,” he added, “came to understand that Obama was a different kind of politician than those people he served with in the Senate for all those years, but Obama had his strengths.”
Mr. McDonough said Mr. Obama genuinely believed picking Mr. Biden was his best decision. “It doesn’t mean there’s no tension,” he said. “That’s kind of the point. If you’re going to have a partner, there’s going to be tension. And it’s in the tension and in the turbulence that the relationship strengthens and ideas get better.”
The bond grew tighter when the vice president learned his son Beau had a brain tumor. Mr. Biden confided in the president, but few others. If the vice president arrived late for a morning intelligence briefing, Mr. Obama made eye contact as if to say, “Are you O.K.?”
“They got to the point that they could speak without actually saying anything,” Mr. Rhodes said.
When Mr. Biden weighed selling his house in Delaware to help Beau’s family, Mr. Obama offered to pay off the mortgage himself. When Beau died at age 46, it felt like a blow to Mr. Obama, too. “Joe,” an uncharacteristically emotional president told him during the eulogy, “you are my brother.”