WASHINGTON — In an uncommon transfer by a committee chairman within the president’s personal occasion, Senator Ron Wyden of Oregon is refusing to schedule a listening to for President Biden’s nominee to run U.S. Customs and Border Safety till the administration solutions questions concerning the federal response to the unrest in Portland, Ore., final summer time.

Mr. Wyden, a Democrat and the chairman of the Senate Finance Committee, notified the White Home this week of his choice to delay a listening to for Chris Magnus, the police chief in Tucson, Ariz. Mr. Biden nominated Chief Magnus in April to run the company, which performs a central function in addressing the inflow of migrants on the nation’s southern border.

Mr. Wyden stated that for months, he had been asking officers from the Justice and Homeland Safety Departments to reply particular questions on how the businesses, beneath former President Donald J. Trump, ready for the extraordinary step of sending federal regulation enforcement officers into the streets of Portland, and what occurred on the bottom, when protests there turned violent after George Floyd’s homicide by a police officer in Minneapolis.

Standing up a military-type presence in the course of downtown protests in opposition to police violence stays one of the crucial contentious choices that Mr. Trump made throughout his time in workplace.

“Six months into the brand new administration, the Division of Homeland Safety and Justice have did not reply fundamental questions on how the Trump administration misused federal assets to stoke violence in opposition to peaceable protesters in my hometown,” Mr. Wyden stated in an announcement on Wednesday.

Mr. Wyden is a liberal who holds one of the crucial highly effective posts within the Senate. He was elected to the chamber in 1996 after serving within the Home since 1981, the place he represented a district that features elements of Portland.

“Whereas it’s clear that Customs and Border Safety faces urgent points,” he stated within the assertion, “because the senior senator from Oregon, I’m unable to advance this nominee till D.H.S. and D.O.J. provides Oregonians some straight solutions about what it was as much as in Portland final 12 months, and who was accountable.”

The transfer by Mr. Wyden comes because the move of migrants throughout the nation’s southern border has surpassed the height ranges of current years. The Border Patrol, which is a part of Customs and Border Safety, caught migrants crossing into the nation more than 178,000 times with out documentation in June, essentially the most apprehensions since April 2000.

The administration is planning for how it will lift a public health order put in place firstly of the pandemic, which it has used to show again migrants on the border a couple of million occasions. Lifting that order will additional improve the variety of individuals attempting to get into the nation, elevating the sense of urgency to get a everlasting chief in place at Customs and Border Safety.

“Given the persevering with humanitarian disaster on the border, there may be an pressing want for his management and experience,” members of the Law Enforcement Immigration Task Force, a gaggle of native regulation enforcement officers that helps an immigration overhaul, wrote of Chief Magnus in an open letter Wednesday.

A 12 months in the past, because the protests in Portland stretched on all through the presidential marketing campaign, Mr. Biden stated Mr. Trump was utilizing “egregious techniques” to handle the unrest in Portland.

“Homeland Safety brokers — with no clearly outlined mandate or authority — are ranging removed from federal property, stripped of badges and insignia and figuring out markings, to detain individuals,” Mr. Biden said in a statement on the time. “They’re brutally attacking peaceable protesters, together with a U.S. Navy veteran.”

Senator James Lankford, Republican of Oklahoma, has positioned a maintain on the nomination of Chief Magnus and a number of other different homeland safety officers till, he stated final week, “we will truly get the Biden administration to put out what their coverage goes to be, and what they’re going to do to have the ability to truly implement the regulation.”

That sort of transfer is typical of senators who will not be within the president’s occasion, however interference from an ally of the president will not be.

A spokeswoman from the Division of Homeland Safety stated the company responded to Mr. Wyden privately final week and “seems ahead to working with him to resolve his considerations.”

Keith Chu, a spokesman for Mr. Wyden, stated the division had offered solely “partial” solutions to the senator’s questions. A Justice Division spokeswoman stated on Wednesday that the company was working with Mr. Wyden’s workplace on his requests.

In accordance with a White Home official, the administration is hopeful that the Senate will cooperate with plans to maneuver ahead with Chief Magnus’s nomination.

Downtown Portland was shuttered for weeks final summer time due to individuals protesting in opposition to police violence after a white Minneapolis police officer killed Mr. Floyd, an unarmed Black man, on Might 25. Whereas the capturing prompted protests across the nation, demonstrations in downtown Portland outlasted these in most different cities.

Positioning himself as a law-and-order president, Mr. Trump described the town as lawless, filled with “anarchists” who “hate our country.” And he praised the actions of armed federal officers from a number of businesses who fired tear fuel into crowds and pulled protesters into unmarked vans. Among the many officers deployed to Portland have been members of a special tactical team from Customs and Border Protection that’s sometimes deployed for operations in opposition to drug smuggling.

Doing so solely incensed the protesters, who had been elevating considerations that fascism was on the rise in the USA.

“The uncoordinated deployment of poorly skilled federal regulation enforcement in Oregon, and in different elements of the nation, mustn’t ever happen once more,” Mr. Wyden wrote in a June 9 letter to Homeland Safety Secretary Alejandro N. Mayorkas.

An inspector general report launched in April discovered that the Homeland Safety Division had the authority to ship federal officers to Portland, however didn’t correctly put together them or coordinate with different businesses.

Whereas the report addressed a few of Mr. Wyden’s questions, he’s looking for extra solutions about who led the brokers on the bottom and whether or not they have been identifiable, with badges and uniforms. He has additionally requested what steering, if any, the officers got about tips on how to work together with protesters and members of the media. And he has requested for an inventory of kit that federal officers used whereas deployed in Portland.

Mr. Wyden has additionally requested concerning the deployment of federal officers to Portland hours after Mr. Biden’s inauguration.

Mr. Mayorkas started a departmentwide assessment in March of the selections that led to the company’s involvement within the Portland protests. The assessment is looking for “to make sure that all D.H.S. regulation enforcement personnel obtain applicable coaching and function pursuant to insurance policies consistent with greatest practices and regulation,” stated Marsha Espinosa, a division spokeswoman. She stated the company “is dedicated to respecting the rights of all people who peacefully train their First Modification freedoms of speech and meeting.”

In Might, Mr. Biden revoked a Trump-era executive order that had paved the way in which for federal regulation enforcement officers to descend on Portland with the acknowledged objective of defending federal buildings and property.