The Senate is set to escalate a long simmering fight over President Trump's judicial nominees.

Republicans are poised to confirm a pick for the influential circuit courts next week without the support of either of the nominee's home-state senators - a first for the Trump era.

Eric Miller is the first appeals judge to get a vote on the Senate floor this year, and the 31st of Trump's presidency. Majority Leader Mitch McConnell (R-Ky.) set up an initial vote on his 9th Circuit nomination for Monday evening.

"The judicial train is running in the committee and it will soon hit the floor," Sen. Lindsey Graham (R-S.C.), the chairman of the Judiciary Committee, told radio host Hugh Hewitt.

Miller's nomination is set to revive a feud over "blue slips," a paper that indicates if a home-state senator supports a nomination.

Though the Senate confirmed several appeals judges who were missing one blue slip last year, Miller would be the first circuit court nominee to be confirmed without getting a blue slip from either senator.

Democrats argue Republicans are trying to defang the minority by moving nominees even if they don't have the support of a home-state senator.

Spokespeople for Sens. Patty Murray (D-Wash.), a member of Democratic leadership, and Maria Cantwell (D-Wash.) confirmed to The Hill on Friday that they did not return a blue slip on Miller's nomination.

Murray first announced late last year that she wouldn't return her blue slip for Miller, arguing that Republicans were trying to place "extreme conservatives" on the court.

"This needs to end. So I am not going to be complicit in this latest rushed process to load the courts with Trump nominees in the lame duck session and I will not be returning the blue slip that signals my approval of this process," Murray said in a statement at the time.

The blue-slip rule - a precedent upheld by Senate tradition - has historically allowed a home-state senator to stop a lower-court nominee by refusing to return the blue slip to the Judiciary Committee.

How strictly the precedent is upheld is decided by the committee chairman, and enforcement has varied depending on who wields the gavel.

But the use of the blue slip has emerged as a flashpoint during the Trump administration as several Democratic senators have refused to return their paperwork on circuit court nominees from their home states, setting up a round of fights between Democrats and the White House.

Democrats went "nuclear" to nix the 60-vote filibuster for district and circuit judges in 2013, leaving the blue slip as one of the few options left for a home-state senator who is in the minority to try and hold up a nominee they oppose.

"We are unilaterally disarming the Senate Judiciary Committee in a way that will have collateral damage well beyond the immediate goal of packing the courts with these nominees in a great rush," Sen. Sheldon Whitehouse (D-R.I.), a member of the committee, said during an hours-long, contentious hearing earlier this month.

Democrats and outside groups say Miller would be the first known example in the roughly 100 years that the blue slip has existed of a circuit nominee getting confirmed without either home-state senator returning the slip of paper.

"There are no known instances in which a nominee has ever been confirmed over the objections of both home-state senators. The Senate must not let Mr. Miller be the first, or it will strip senators of their constitutional role of providing advice and consent for appellate appointments in their states from this and all future administrations," Vanita Gupta, the president and CEO of The Leadership Conference on Civil and Human Rights, wrote in a letter to senators.

Ryan Bounds, a nominee for a different 9th Circuit seat, was poised to be the first last year when the Senate brought his nomination up for a vote without either Sens. Jeff Merkley (D-Ore.) or Ron Wyden (D-Ore.) returning a blue slip. But his nomination was withdrawn after GOP Sen. Tim Scott (S.C.) said he wouldn't support him.

Republicans infuriated Democrats when they held a hearing for Miller during the October recess last year when most lawmakers were out of town. GOP aides argued that Sen. Dianne Feinstein (Calif.), the top Democrat on the panel, had agreed to the dates, but Democrats say they did not agree to move forward if the Senate was not in session.

Only two senators of the then-21-member panel attended the hearing, with Miller only getting asked two questions by Sen. Mike Crapo (R-Idaho). Neither Sen. Chuck Grassley (R-Iowa), who was the chairman at the time, or any of the Democratic senators were there.

Republicans have dismissed complaints from Democrats over moving circuit court nominees despite the objections of home-state senators, arguing that Democrats are trying to apply a standard not enforced by most Judiciary Committee chairmen.

"Now you're complaining about the fact that we won't allow two senators to take over the entire process? The blue slip process for circuit judges are not gonna be allowed to become a veto," Graham said on Friday.

Republicans view the courts as their best shot for the party having a long-term impact.

Appeals courts, in particular, are a top priority for McConnell because the circuit courts hear thousands of cases every year - compared to the Supreme Court, which heard 69 cases during their last term - and often have the final say for states within their jurisdiction.

Republicans set a record for the number of appeals judges confirmed during an administration's first two years and McConnell, speaking at a Heritage Foundation event shortly before the midterms, pledged that "if we hold the Senate I assure you we will complete the job of transforming the federal judiciary."

Miller was one of more than forty nominees that were approved by the Judiciary Committee earlier this month and sent onto the full Senate for a vote. Of those nominations, six were circuit pick nominees.

Graham indicated on Friday that Republicans have approximately eight to 10 circuit nominations to fill in 2019. He's also got looming fights over three 9th Circuit nominees from California after Feinstein and Sen. Kamala Harris (D-Calif.), who is running for president, came out against the administration's picks.

"We've got a real queue. ... Trust me on this, we will get our judges to the floor," Graham added. "Whatever you want to say about Mitch McConnell, he's done a hell of a job when it comes to processing judges."