Judge Brett Kavanaugh, President Trump’s Supreme Court nominee, forcefully defended the National Security Agency’s dragnet collection of domestic call records, alarming privacy advocates who view the collection as unconstitutional.

It’s not yet clear if Kavanaugh’s November 2015 concurrence while serving on the U.S. Court of Appeals for the D.C. Circuit will factor prominently in his confirmation proceedings. But before he was nominated, progressive and conservative advocates expressed concern.

“I believe Judge Kavanaugh is an excellent judge, though certainly not a perfect one,” Ken Cuccinelli, president of the Senate Conservatives Fund, told the Washington Examiner last week. "His Fourth Amendment perspective is troubling."

“As someone who sued the NSA over their metadata gathering as a violation of the Fourth Amendment, he and I disagree on that point, and I think a lot of liberty-minded folks are going to have that as a major concern,” said Cuccinelli, a former Virginia attorney general.

Privacy activists said Kavanaugh's two-page opinion was remarkable both for its legal analysis and the fact he didn’t need to write it. He attached the concurrence to a legal order turning down an appeal challenging the NSA’s then-discontinued call record dragnet.

The other appeals court judges offered no reason for denying the appeal, but Kavanaugh voluntarily wrote that he believed the collection, which Congress ended as a matter of policy earlier that year, was constitutional.

The dragnet ingested and stored for five years domestic phone call metadata for potential later use in intelligence investigations, but there was no evidence it ever helped foil a terror plot against the U.S.

Kavanaugh wrote that the dragnet collection did not constitute a “search” under the Fourth Amendment, citing the third-party doctrine established by the Supreme Court's 1979 decision in Smith v. Maryland — a common perspective among judges.

But he added that even if it was a “search” under the Fourth Amendment, the government was allowed to take the records because it had a “special need” in preventing terrorism, overriding the privacy interests of people whose records were taken without a warrant.

George Washington University law professor Jonathan Turley said that Kavanaugh’s concurrence “reflects a sweeping view of national security as an exception to core protections.”

“The concurrence is particularly notable because it is largely dicta,” Turley went on. "Kavanaugh went out of his way to position himself at the outer limits of executive power.

“Notably, it runs against the type of protective approach of recent cases like Carpenter,” he added, referring to a Supreme Court ruling from last month requiring a warrant for authorities to collect cellphone location data.

Some members of the Senate argued strongly against the call record program, including Sens. Mike Lee, R-Utah, and Rand Paul, R-Ky.

Jameel Jaffer, executive director of the Knight First Amendment Institute at Columbia University, previously represented the American Civil Liberties Union in a lawsuit against the call record collection. He said it would be incongruous for Trump to express concern about surveillance practices, then nominate a forceful backer of the discontinued historical dragnet.

“I don’t want to take a position on the viability or merit of any particular possible nominee, but I think it would be odd and incoherent for a president who has expressed so much concern about the abuse of surveillance power to nominate a judge who went out of his way to declare that he was untroubled by the NSA’s dragnet collection of hundreds of millions of Americans' call records,” Jaffer said last week.

Trump nominated Kavanaugh less than a week after taking a very different approach to government surveillance, calling the NSA’s recent purge of call records “a disgrace,” tweeting about claims of accidental over-collection: “Privacy violations? They blame technical irregularities.”

The once-secret call record program defended by Kavanaugh was exposed by former NSA contractor Edward Snowden in 2013 and was sharply curtailed by Congress in June 2015 amid privacy concerns.

"The fact that this would be overlooked is outrageous," said conservative legal activist Larry Klayman, whose case Kavanaugh rejected, after a lower court judge found the collection likely violated the Fourth Amendment.

"It's the Republican inside-the-beltway establishment that pushed [Trump] into doing this," Klayman said. "President Trump has sown the seeds of his own destruction because Kavanaugh would have found the surveillance on him perfectly acceptable."

Klayman added: "He didn't have to write that opinion. He made a special effort to write an opinion that rubber stamped mass surveillance on the American people and he did that for political reasons to curry favor with the establishment."

Attorney Miguel Estrada, a Kavanaugh supporter nominated unsuccessfully for a federal judgeship in 2001, defended Kavanaugh’s surveillance opinion, telling the Washington Examiner last week that his "special need" analysis seems to fall in line with court precedent.

"Judge Kavanaugh was merely pointing out — quite correctly — that the collection of telephone numbers that one dials is not considered a search under the Supreme Court’s decisions in Smith v. Maryland, and that even if it were, the Supreme Court has also developed a 'special needs' doctrine under the Fourth Amendment that would seemingly apply here," Estrada said.

"If this exemplifies 'deference,' it is deference to the Supreme Court, whose decisions are binding on lower court judges, not deference to the executive branch," Estrada continued. "I note that even after the Supreme Court’s very recent decision in Carpenter, Smith v. Maryland continues to be good law. The Supreme Court was urged to overrule it but did not do so."

Orin Kerr, a Fourth Amendment scholar at George Washington University, said that the brevity of Kavanaugh’s concurrence made it difficult to thoroughly analyze his viewpoints, but that “Kavanaugh's view was more national-security oriented than privacy oriented, certainly.”

Kerr said that Kavanaugh’s determination that a “search” did not occur was consistent with Supreme Court precedent — “although at least in academic circles that view was controversial.”