The Senate on Tuesday confirmed Nathan Simington as a new Republican member of the Federal Communications Commission, a move that threatens to saddle the nation’s foremost telecom regulator with political deadlock at the start of the Biden administration.

The chamber backed Simington on a 49-to-46 vote, installing a new commissioner at the FCC who has pledged “regulatory stability” and expressed an openness to using the agency’s rulemaking powers to explore the way social media sites handle political speech.

Simington’s confirmation comes as the FCC’s GOP chairman, Ajit Pai, is preparing to leave in January. The two staffing moves combined will leave the five-member agency at two Democrats and two Republicans at the start of next year, curtailing the commission’s ability under Joe Biden to carry out the party’s telecom agenda as soon as he is inaugurated as president.

The deadlock could slow or stall work on restoring net neutrality rules, which require Internet providers to treat all Web traffic equally, and other longtime Democratic priorities. Its duration ultimately hinges on party control of the Senate and the outcome of two runoff elections in Georgia.

Andrew Jay Schwartzman, senior counselor at the Benton Institute for Broadband & Society, said a GOP-run Senate would make it difficult for Biden to fill the agency’s fifth slot — allowing Republicans to “tie things up for an extended period of time, perhaps indefinitely,” at the telecom agency.

The last-minute race to confirm Simington comes as Trump ratchets up his attacks on Silicon Valley over allegations that it exhibits political bias against conservatives. Trump had initially proposed that Michael O’Rielly, a sitting GOP commissioner, serve another term at the agency. But O’Rielly delivered a speech this summer that raised red flags about government intervention in online content moderation, prompting the president to pull O’Rielly’s nomination in early August.

In September, Trump tapped Simington, an aide at the Commerce Department who played a critical role in carrying out Trump’s executive order over the summer that sought to expand the U.S. government’s power to police online speech. The president took an unexpected interest in his confirmation, tweeting repeatedly that the Senate needed to act to confirm him for the FCC.

Appearing at a Senate confirmation hearing last month, Simington told lawmakers that he would take a deregulatory approach to the telecom industry as he focused on issues such as broadband connectivity and national security. He promised to be “thoughtful about potential chilling effects on development if [the FCC’s] regulatory efforts go over the line and become intrusive, disruptive and burdensome.”

And he signaled to GOP lawmakers, including Sen. Ted Cruz (Tex.), that he would support any effort at the FCC to try to reexamine Section 230. The agency has been exploring the issue amid months of public pressure from Trump, who in recent days has threatened to veto an annual defense policy bill unless it repeals the law.

The timing of Simington’s nomination — and his past work and public comments on political speech — have greatly troubled Democrats. Party leaders mounted a last-minute effort this week to question his political independence and stop his confirmation. Appearing at a news conference Monday, Sen. Richard Blumenthal (Conn.) called him “deeply dangerous,” and Sen. Brian Schatz (Hawaii) charged he “has no qualifications beyond his loyalty to an outgoing wannabe autocrat.”