Ajit Pai, the Trump-appointed Republican chairman of the FCC, announced that he will leave the agency on Jan. 20, 2021, when president-elect Joe Biden is sworn into office.

Pai’s exit, which will likely give the Democrats a 3-2 majority at the FCC, was expected: It’s customary for political appointed heads of agencies to step down with a changeover in presidential administrations.

Beltway insiders have identified Jessica Rosenworcel, the senior Democrat on the commission, as one of the leading candidates to succeed Pai as chair of the FCC. Another contender is Mignon Clyburn, who served on the commission from 2009-18. She is the daughter of House Majority Whip James Clyburn, whose endorsement of Biden was key to his securing the Democratic presidential nomination. Mignon Clyburn has been named to Biden’s transition team for the FCC.

The biggest controversy under Pai’s tenure at the FCC helm was the commission’s December 2017 vote along party lines to repeal net neutrality, the standard that barred internet service providers from creating “fast lanes” for certain content companies or blocking or throttling content. With Democrats taking control of the FCC, the agency’s net neutrality order is expected to be swiftly reinstated.

Pai, in calling for the repeal of the FCC’s 2015 Open Internet Order, accused the agency of bowing to pressure from President Obama and said that “it imposed heavy-handed, utility-style regulations upon the internet. That decision was a mistake. It’s depressed investment in building and expanding broadband networks and deterred innovation.”

The FCC was flooded with almost 23 million comments on its net neutrality proceeding, a record for the agency, although millions of those were bogus and reportedly submitted by both anti-net neutrality industry organizations and net neutrality supporters. (According to the New York Attorney General’s Office, as many as 9.6 million comments may have used stolen identities.) Pai said he and his family were harassed over the rollback of net-neutrality rules and in 2018 a man was arrested for allegedly threatening to kill the FCC chairman’s children.

Pai was designated the FCC’s chairman by President Trump in January 2017. He had previously served as commissioner at the FCC, appointed by then President Barack Obama and confirmed unanimously by the Senate in May 2012. The son of immigrants from India, Pai grew up in Parsons, Kan., and currently resides in Arlington, Va.

In a statement, Pai said, “I am grateful to President Trump for giving me the opportunity to lead the agency in 2017, to President Obama for appointing me as a Commissioner in 2012, and to Senate Majority Leader McConnell and the Senate for twice confirming me. To be the first Asian-American to chair the FCC has been a particular privilege. As I often say: only in America.”

Under Pai, the FCC has publicly published drafts of proposals and orders slated for a vote three weeks before the agency’s monthly meetings — and observers credit Pai for the change to make the commission far more transparent about its proceedings. In addition, as chairman, Pai led the FCC’s five spectrum auctions and two rural broadband reverse auctions over the past four years and opened up 1,245 megahertz of mid-band spectrum for unlicensed use. The FCC also designated 988 as the three-digit number for the National Suicide Prevention Lifeline on Pai’s watch.

But critics say Pai’s stated goals of closing the digital divide, promoting competition, and supporting public safety have fallen short. For example, he backed T-Mobile’s acquisition of Sprint, which consumer advocates argued will lead to higher prices and fewer choices for Americans.

Pai stood up to Trump when the president suggested in October 2017 that NBC and other TV broadcasters should have their spectrum licenses revoked because Trump was unhappy with their news coverage.

But more recently, Pai supported Trump’s call for the FCC to reinterpret U.S. law to let the commission regulate social media companies, after the president was angry that Twitter and Facebook were fact-checking his posts. In October, less than three weeks before the presidential election, Pai announced he was initiating an official FCC rulemaking seeking to “clarify” how Section 230 of the Communications Decency Act applies to social media companies. As currently interpreted, Section 230 grants internet companies broad legal protections for user-posted content on their services.

“Social media companies have a First Amendment right to free speech,” Pai said in a statement at the time. “But they do not have a First Amendment right to a special immunity denied to other media outlets, such as newspapers and broadcasters.”

Rosenworcel blasted Pai’s announcement, saying, “The timing of this effort is absurd. The FCC has no business being the President’s speech police,” and the ACLU said the FCC has no authority to change Section 230 or impose any kind of content-moderation regulations on social media networks.