Over the weekend, I was shocked and saddened to learn that Doug Kendall, founder and president of the Constitutional Accountability Center, had died from complications of colon cancer. I knew that Doug had had some health problems earlier in the year, but wasn’t aware of their continuing severity.

Doug started CAC, a public-interest legal organization devoted to the idea that the text and history of the Constitution shows our Founding document to be profoundly progressive, as a successor to his more narrowly focused Community Rights Counsel. He, along with his colleagues, have become among the closest “frenemies” of Cato’s Constitutional Studies Center.

As Randy Barnett notes, even though Doug and CAC are typically at loggerheads with libertarian thinking, they compete on the same originalist playing ground. The battle is joined fairly and honestly, and even when I’ve most vehemently disagreed with Doug, Elizabeth Wydra, David Gans, Simon Lazarus, Brianne Gorod, and the rest of CAC’s formidable team, I’ve known that they approach their vocation with rigor and integrity. (Alas, I can’t say this about all the critics of Cato’s legal positions.)

And there are times when we’ve been aligned. The battle to restore the proper understanding of the Privileges or Immunities Clause in the context of the right to keep and bear arms (McDonald v. Chicago) was one. Same-sex marriage was another, including when we joined together to file briefs in Perry v. Hollingsworth and United States v. Windsor to make common cause regarding the Equal Protection Clause. (As we illustrated in the 2012–2013 Cato Supreme Court Review, Cato and CAC don’t always agree, but when we do, it’s the most interesting brief in the world.) I’ve often joked that after taking on guns and sex together, with a focus on two of the Fourteenth Amendment’s main provisions, the next time we join forces will be on a drug case relating to the Due Process Clause.

Doug Kendall was a man of principle who lived his ideals. My condolences go out to his wife, daughter, and extended family and friends.