President Joe Biden has pulled the nomination of gun-control advocate David Chipman to head the Bureau of Alcohol, Tobacco, Firearms and Explosives, Reuters reports, according to two people with knowledge of the decision. The Washington Post, The Associated Press, and other outlets also reported Biden’s impending move Thursday, citing multiple unnamed sources. Chipman had faced strong Republican opposition in the Senate, undermining his chances of winning confirmation in a chamber only narrowly controlled by Biden’s fellow Democrats. Republicans generally oppose gun control measures. Biden has called U.S. gun violence a “national embarrassment.” The two sources, speaking to Reuters on condition of anonymity, confirmed that Chipman’s nomination had been withdrawn. One of the sources noted that Sen. Angus King of Maine, an independent who generally votes with the Democrats but was a holdout on Chipman, was a key factor in the decision to withdraw the nomination. “Angus King is the main reason our most qualified ATF director in its history is not assuming this role,” the source said. The White House declined to comment on the matter.