WASHINGTON — Louisiana U.S. Sen. John Kennedy lambasted several of the Trump administration's picks for the federal judiciary, calling one nominee "embarrassing" and questioning the competency of the White House office charged with vetting potential judges.

Kennedy became the first GOP senator to vote against a Trump administration nominee for a federal judgeship Tuesday night, turning down his thumb at Gregory Katsas' nomination for the powerful D.C. Circuit Court of Appeals.

The senator said Katsas, an attorney who currently serves as deputy counsel to President Donald Trump, would have an inherent conflict of interest on the appeals court because of its extensive jurisdiction over matters involving the White House.

The Senate confirmed Katsas to the post, 50 to 48, despite Kennedy's vote. Democratic Sen. Joe Manchin of West Virginia broke ranks with his party to back Katsas.

"I think his credentials are extraordinary, I think he does an extraordinary job for President Trump," Kennedy said of Katsas, "But to me there’s an appearance of a conflict if on one day he’s representing the president and the next day he’s on the D.C. Circuit deciding cases in which the president is a party."

Kennedy, speaking with a gaggle of reporters in the basement of the U.S. Capitol just after casting his vote against Katsas, pledged to oppose another White House pick for a federal judgeship in Alabama.

The senator also hinted at potential opposition to Kyle Duncan, a nominee for a Louisiana seat on the Fifth Circuit Court of Appeals. Duncan is set to appear before the Senate's Judiciary Committee Wednesday.

Kennedy said he's impressed with the "pro-life and pro-religious freedom" qualifications of Duncan, a 45-year-old LSU law school graduate who has become a major Washington-based legal warrior on conservative social issues.

But Kennedy questioned Duncan's ties to the state, saying he's received "a lot of calls" from Louisiana attorneys and judges with extensive experience and comparable conservative credentials. Appointments to the federal bench are highly prized among lawyers and seats on appellate courts like the Fifth Circuit are lifelong ambitions for many.

Except for a several-year stint working for former Louisiana Attorney General Buddy Caldwell, Duncan has spent nearly all of his professional career outside Louisiana and has been based in Washington for the past several years.

"'So how come you’re picking a Washington lawyer — what am I, chopped liver?'" Kennedy said Louisianans have asked him. "And I’ve got to be able to answer that from those people."

Although Kennedy told Judiciary Committee Chairman Chuck Grassley, R-Iowa, he has no objections to holding a hearing for Duncan, the Louisiana senator has so far withheld his support.

Kennedy highlighted Brett Talley, a White House pick for a lifetime federal district court appointment in Alabama, as an example of White House nominees "that have no business being on a federal bench."

Numerous questions have been raised about Talley's qualifications. Talley, an attorney, has never tried a courtroom case. He also didn't note that his wife, Annie Donaldson, works in the White House as chief of staff to White House Counsel Don McGahn.

Kennedy said he'd vote against Talley "in a heartbeat — and twice if I could."

Kennedy said he supported Talley in the Judiciary Committee only because he was never told about his wife's position and because other disqualifying information hadn't come to light. Kennedy referenced a Slate.com report indicating Talley may have defended the Klu Klux Klan in voluminous posts to an online message board.

"Give me a break!" Kennedy said. "It is embarrassing and I think the president of the United States is getting some very, very bad advice."

Kennedy said he'd tried to raise these concerns with McGahn, the White House counsel, whose office handles potential nominees for the federal bench. But the senator said those conversations haven't been productive.

"It's like talking to the wind," Kennedy said.

Follow Bryn Stole on Twitter, @BrynStole.