WASHINGTON – U.S. Sen. Al Franken will not back a Minnesota Supreme Court justice who is President Donald Trump's pick for a federal judgeship.

Franken, D-Minn., announced Tuesday that he will oppose the nomination of Justice David Stras to the Eighth U.S. Circuit Court of Appeals, saying he finds Stras too conservative for an already conservative bench. By Senate tradition, Franken's opposition effectively derails the nomination of Stras.

"The president should be seeking out judges who bridge the issues that divide us," Franken said in a statement Tuesday. "I fear that Justice Stras's views and philosophy would lead him to reinforce those divisions and steer the already conservative Eighth Circuit even further to the right."

Stras, who once clerked for U.S. Supreme Court Justice Clarence Thomas, is well regarded by colleagues from both sides of the aisle, who have called him a fair-minded scholar and consensus builder. A White House spokesperson told the Star Tribune the Senate Judiciary Committee should hold hearings on Stras with or without support from Minnesota's senators.

"Senator Franken's opposition to Justice Stras is partisan, obstructionist politics at its worst," the spokesperson said on background, after reeling off a long list of the justice's professional and personal merits. "David Stras is as qualified it gets. He deserves a chance to have a hearing so the American people can see that for themselves."

Senate protocol dictates that both home-state senators must sign off on judicial nominees from their state — a process known as "blue slipping." When presidents and senators are from opposing parties, the wait for a blue slip can stretch for months or years, as a number of Obama-era judicial nominees discovered.

Stras declined to comment through a spokesman.

Sen. Amy Klobuchar, also a Democrat and like Franken a member of the Senate Judiciary Committee, said she thought Stras deserved a hearing.

After studying his record, Klobuchar said in a statement Tuesday, "I learned that for the vast majority of the cases he has respected precedent and sided with the majority, which has included both Democratic- and Republican-appointed judges. He is also supported by former Supreme Court Justice Alan Page." That was reflected in a letter to the Senate supporting Stras from dozens of Minnesota attorneys and jurists, who wrote that "Justice Stras has distinguished himself not only as a top-notch jurist, but as a judge who decides cases without regard to political affiliation or party lines."

The Eighth Circuit is one of 12 courts that review cases decided in the country's 94 federal district courts. The Eighth Circuit has eight active judges and five senior judges, and covers seven states including Minnesota, Iowa and the Dakotas.

The vacancy was created when Judge Diana Murphy took senior status, a form of semiretirement for federal judges, last year after 12 years. Murphy is one of two Eighth Circuit judges based in Minnesota. The other, James Loken, has been an active judge since 1990.

Klobuchar said she's worried that the Republican White House will now fill the vacant seat on the Eighth Circuit with a jurist from a neighboring state like Iowa, Arkansas or South Dakota — all states with two Republican senators.

That prospect also worries Ronald Schutz, a Minneapolis attorney and former chair of the Minnesota Judicial Selection Commission under Republican Gov. Tim Pawlenty. Franken's blue slip denial was "an unfortunate development," he said.

"I do not think President Trump will be able to find a lawyer or judge from Minnesota who shares his judicial philosophy and who will be acceptable to our two Democrat Senators," Schutz said in an e-mail. He went on that it likely "means that Minnesota loses a seat on the 8th Circuit. Thank you Senator Franken."

The circuit court is just one of the seats that remain unfilled since the start of the Trump administration. Minnesota also lacks a U.S. attorney and U.S. marshal, and is short two federal district court judges.

Trump nominated Stras to the Eighth Circuit in May, after the 43-year-old judge's name was first floated as a potential U.S. Supreme Court nominee. Pawlenty put Stras on Minnesota's high court in 2010.

Franken's decision provoked scorn from conservative legal groups that repeatedly criticized the Minnesota delegation for not signing off on the nomination. In recent years, U.S. senators from both political parties have frequently slowed down or blocked judicial nominees by presidents from the other political party.

Klobuchar and Franken pushed back against criticism, noting that the White House didn't seek input from the home state senators before nominating Stras.

"I had hoped that, in recognition of our different views, President Trump would work with me to identify a consensus candidate — a nominee whose experience demonstrates an ability to set aside rigid beliefs in favor of finding common ground," Franken said.

Minnesota Republican Party Chairwoman Jennifer Carnahan blasted Franken for blocking the nomination.

"In refusing to support Justice Stras for appointment to the 8th Circuit Court, Al Franken's actions exhibit the worst form of partisanship," Carnahan said in a statement, noting that Franken had called Stras a committed public servant.

It was not immediately clear if Republicans who control the U.S. Senate would continue to honor the blue-slip tradition. Klobuchar said she will urge Senate Judiciary Chairman Chuck Grassley to preserve the two-senator requirement for judicial nominees, which has been in place for the past decade — rather than modifying or scrapping the tradition, as some critics have urged.

And she wished Stras well — back home in Minnesota.

"I have enjoyed getting to know Justice Stras throughout this process and I know he will continue to serve admirably on the Minnesota Supreme Court," she said.

jennifer.brooks@startribune.com 202-662-7452

stephen.montemayor@startribune.com 612-673-1755