Justice took the oath of office one day after he finished his second term as West Virginia governor and six days before President-elect Donald Trump is inaugurated for a second term as president.

Other freshman senators were sworn in on Jan. 3, the first day of the new Congress, but Justice stayed behind in West Virginia to simplify the transition of power to his successor, Gov. Patrick Morrisey (R-WV).

Had Justice resigned early, West Virginia would have had four governors in 10 days, with two state Senate presidents serving in the role in an acting capacity.

Justice is one of four Republicans who flipped Democratic seats in the 2024 elections, solidifying GOP control of the Senate. His predecessor, Joe Manchin, was the last Democrat to hold statewide office in West Virginia.

Justice joins the Senate as Republicans prepare to usher Trump’s Cabinet nominees across the Senate floor.

He will evaluate Chris Wright, nominated for energy secretary, on Wednesday as a member of the Energy and Natural Resources Committee. One day later, Justice will attend the confirmation hearing for Doug Burgum, Trump’s interior secretary nominee.

Justice is not the only senator to join the Senate late. Republicans will have their entire majority in place once Ohio Gov. Mike DeWine (R-OH) chooses a successor to Vice President-elect J.D. Vance, who will be inaugurated next Monday.

There will be yet another opening if Sen. Marco Rubio (R-FL) is confirmed as Trump’s secretary of state.

Justice, a West Virginia coal baron, plans to focus on domestic energy production in his first term, describing the United States as the Saudia Arabia of natural gas in a recent interview with the Washington Examiner.

Beyond the Energy and Natural Resources Committee, Justice also holds seats on the Senate’s agriculture, small business, and aging panels.