When Joseph Onek heard that the U.S. Supreme Court had tapped his former law partner to brief and argue an issue in the blockbuster healthcare challenge, he called him to offer congratulations and some names of experts as resources in the complex case.

But H. Bartow Farr III, in characteristic style, declined. “He said, ‘No, I’ll just have to learn it,’ ” said Onek, a principal at the Raben Group in Washington. “ I’m sure he read everything written about the law. He didn’t want anybody to think he was swayed by people with potential agendas. I’m sure he did it the old-fashioned way.”

Farr is a “lawyer’s lawyer, not a political lawyer or even a Washington lawyer,” said Onek.

The justices appointed Farr of Washington, D.C.’s Farr & Taranto, to defend a ruling by the U.S. Court of Appeals for the 11th Circuit that the main parties in the fight over the Patient Protection and Affordable Care Act did not support. The appellate court, in striking down the so-called individual mandate to purchase health insurance, ruled that the mandate was severable from the rest of the act. Farr will defend the severability of the mandate in arguments on March 28.

“He is a perfect choice for this,” added Onek, who with Farr and Joel Klein, formed Onek, Klein & Farr, one of the first Supreme Court practices three decades ago. “He has not been involved in the case in any way. He will simply analyze it and make the best argument.”

Farr, 67, may have one of the lowest profiles and highest reputations among the Supreme Court bar today. As a rule, he does not talk about his cases with the media before arguments. And in the media crush surrounding arguments over the healthcare challenge, he seems even more determined to keep a low profile, in contrast to the frequent public discussions in which his counterparts have engaged.

“He is basically the guy I learned to write briefs from,” said Paul Smith, head of the Supreme Court and appellate practice at Jenner & Block. “I went [to his firm] straight from clerking for Justice (Lewis) Powell.”

Smith describes Farr as a careful stylist who does his own brief writing and who is very meticulous. “His focus was making sure things were linear and clear,” he added. “There is nothing extra in them. He argues that way too. He is a little formal in argument. He has his points. You can always trust what he says.”

After graduating from Princeton, Farr headed to Arizona for law school at Arizona State University School of Law. He was editor-in-chief of the law review and graduated summa cum laude. After law school, he clerked for then-Associate Justice William Rehnquist from 1973 to 1974. In 1976, he joined the Department of Justice as an assistant to the solicitor general and argued five cases for the government in the Supreme Court before leaving in 1978. Moving into private practice, Farr teamed up with Onek and Klein to form the boutique appellate litigation firm of Onek, Klein & Farr.

“They were really on the cutting edge of Supreme Court practices,” recalled Smith, adding that former Solicitor General Rex Lee soon would follow by joining Sidley Austin, and a group of lawyers from the solicitor general’s office also would launch a high court practice at Mayer Brown.

When Onek left the firm, Farr and Klein added two partners, Smith and Richard Taranto. In 1994, Smith left for Jenner & Block and Klein joined the Justice Department. The firm became today’s Farr & Taranto (Taranto has been nominated to the Federal Circuit by President Obama). The earlier changes in the firm generally stemmed from disagreements over growth.

“They did not want to have a big, institutional establishment,” said Smith. Onek agreed, saying of Farr, “What he wanted to do and what he cared about did not require a large firm.”

Farr has argued 30 cases in the Supreme Court, including PGA Tour v. Martin, U.S. v. Eurodif S.A., and New Jersey v. Delaware. He is variously described as very funny, witty, a sports fanatic and an athlete (“We used to have annual tennis parties at his house,” said Smith.”

“He is incredibly demanding because his standards are so high, but that doesn’t grate on people because he is invariably correct and they understand his standards are high,” said Onek. “His greatest love is to sit in a corner and write his briefs. I doubt there is any time he is happier.”

Marcia Coyle can be contacted at mcoyle@alm.com.