The nomination of David Chipman, President Joe Biden’s pick to lead the Bureau of Alcohol, Tobacco, Firearms, and Explosives, is on shaky ground as rural state Democratic senators voice their doubts about the gun control advocate.

It threatens to be one of only a handful of confirmation defeats for Biden during his first six months-plus in office. A majority of senators also refused to confirm Biden’s choice for director of the Office of Management and Budget, liberal activist and former think tank president Neera Tanden.