Is it time for the Supreme Court to have a detailed, binding code of ethics?

That’s a question sparked by the recent report from ProPublica that in 2008, Justice Samuel Alito took a luxury fishing trip to Alaska on a billionaire’s private jet.

Justice Alito did not report the trip on his financial disclosure. That may have violated a federal law that requires justices to disclose most such gifts, according to the ProPublica story.

Nor did Justice Alito recuse himself when cases involving businesses of the billionaire, Paul Singer, came before the court. In 2014, justices voted 7-1 in favor of Mr. Singer’s hedge fund in a lawsuit that ultimately netted it $2.4 billion.

Justice Alito has denied that he did anything wrong. In a prebuttal in The Wall Street Journal published prior to ProPublica’s release of the story – an unusual step – he said that the trip was personal hospitality, and thus he didn’t need to report it. He wasn’t aware Mr. Singer had any interest in the cases before the court, he insisted.

There’s been a code of conduct for federal court judges since 1973, but the Supreme Court isn’t bound by it. That should change, say some experts, given the allegations against Justice Alito and recent revelations about gifts to Justice Clarence Thomas from billionaire Harlan Crow.

This isn’t about attacking the court’s conservative majority, some insist. Justice Sonia Sotomayor has not recused herself from court cases involving publisher Penguin Random House, which has paid her millions in book royalties.

“A demand for ethical constraints is not an attack on the Court or any single justice. It is simply common sense,” said the watchdog group Project on Government Oversight earlier this month.