Senate Judiciary Committee Chairman Charles E. Grassley (R-Iowa), left, and ranking Democrat Sen. Dianne Feinstein (Calif.), on right. (Chip Somodevilla/Getty Images)

The Senate Judiciary Committee on Thursday approved the nomination of Ryan Bounds to serve on the U.S. Court of Appeals for the 9th Circuit, likely setting up the confirmation of the first federal judge to ascend to the bench over the objections of both home-state senators in over a century.

The famously liberal 9th Circuit covers nine Western states from Hawaii to Arizona and is based in California. Bounds, now an assistant U.S. attorney in Oregon, was nominated for the seat that has traditionally gone to an Oregonian. While he was born in and spent much of his career in the state, he failed to secure the support of either Oregon senator — both of whom are Democrats.

Bounds is only the latest controversial judicial nominee whom Republican leaders have pushed through the confirmation process on party-line votes over the objections of Democrats. In Bounds’s case, Democrats point to his track record of legal advocacy for conservative causes and clients and several opinions he published in college that disparaged minorities and sexual assault victims — articles Bounds has since tried to disavow.

But Democrats say they find Bounds’s nomination particularly offensive because they believe it will set a precedent that lawmakers are powerless to influence the selection of federal judges in areas they represent.

“If we do away with blue slips, and that appears to be where we’re going, then what will stop the administration from appointing a resident of New York to Iowa’s 8th Circuit seat?” Sen. Dianne Feinstein (D-Calif.), the panel’s ranking minority-party member, asked before Thursday’s 11-to-10 vote — addressing the comment to Republican Chairman Charles E. Grassley, who is from Iowa.

“When you disable the only mechanism that assigns the circuit court seats to a state and provides some means of enforcement, it’s just incredibly easy for this president or another president to say … let’s just put my college roommate from wherever into whatever seat,” said panel member Sen. Sheldon Whitehouse (D-R.I.). “There’s no principled way to defend against that if you have thrown the blue slip under the bus.”

The “blue slip” to which Feinstein and Whitehouse referred is a physical piece of blue paper, given to senators from the home state that would be represented by a federal district judge or circuit court nominee. Since 1917 it has been a custom, though not a rule, that the Senate Judiciary Committee chairman waits to schedule a nominee for a confirmation hearing until those blue slips are returned favorably.

But Senate Majority Leader Mitch McConnell (R-Ky.) has put a premium on moving Trump’s judicial picks through the Senate, capitalizing on a 2013 rule change that allows all nominees but those to the Supreme Court to be confirmed with a simple majority vote. Grassley has also stated, and repeated Thursday, that he “will not let home state senators have ideological reasons for not returning the blue slip.”

Bounds is not the first nominee who has moved through the confirmation process despite Democrats’ refusal to return a blue slip — earlier this year, the Senate confirmed David Stras to the 8th Circuit despite former senator Al Franken (D-Minn.) never having consented to the nomination. But in that case, the other home state senator — Sen. Amy Klobucher (D-Minn) had consented.

Bounds’s case serves as a potential harbinger for what could happen with the 9th Circuit, where seven of the 29 seats on the bench are currently vacant and another will be by the end of the summer. Ten of the 18 senators representing the states under the circuit’s jurisdiction are Democrats, and six of the eight current and expected vacancies traditionally belong to states represented by Democrats alone.

So far, Trump has nominated only two people to fill those vacancies: Bounds, and Mark J. Bennett, who previously served as attorney general of Hawaii. But should Republicans use Bounds’s confirmation as precedent, it could create a situation in which Democrats have no ability to slow an ideological overhaul of the 9th Circuit bench.

“I urge my colleagues to think of the consequences,” Feinstein said. “Not just for the administration but for the future of our judiciary if we continue down this road.”

Correction: An earlier version of this story misidentified the senator who consented to David Stras’s judicial nomination. It has been corrected.