Mr. Adler is a member of Checks and Balances, a group recently formed by George T. Conway III, a conservative lawyer who is a critic of Mr. Trump. Its members, more than a dozen prominent right-leaning lawyers, are urging their fellow conservatives to speak up about what they say are the Trump administration’s betrayals of bedrock legal norms.
John B. Bellinger III, a top State Department and White House lawyer under President George W. Bush who is also a member of the group, said that the statement from the chief justice was unusual, but appropriate. “Chief Justice Roberts was expressing the same concerns about the president’s attacks on important American institutions that motivated us to form Checks and Balances,” he said.
In a tongue-in-cheek post on Twitter, the group said on Wednesday that perhaps Chief Justice Roberts should join.
There is mounting evidence that some conservatives want to distance their judiciary achievements from Mr. Trump and his personal legacy, said Amanda Hollis-Brusky, a professor at Pomona College and the author of “Ideas With Consequences: The Federalist Society and the Conservative Counterrevolution.”
“While the conservative legal community is very excited about the judges and justices Trump has appointed, I think the formation of this group, and Roberts speaking out, are a recognition that this doesn’t mean the judges and justices are beholden to this president,” she said.
In the aftermath of the highly politicized confirmation vote for Justice Kavanaugh, which stirred up partisan rancor in the Senate and the public, the chief justice’s decision to stand up to Mr. Trump was helpful, said Ilya Somin, a law professor at George Mason University who is associated with the Federalist Society, an organization of conservatives and libertarians whose members have wielded tremendous influence over Mr. Trump’s judicial decisions.
“I have my disagreements with Roberts, but I do think he has a long-term view of what he thinks is necessary to maintain the Supreme Court, and the federal courts generally, as an institution,” Mr. Somin said.