That and he would have made a horrible director. His support among some Democrat Senators, at least privately, was waning. He is a zealous lobbyist, and current and former ATF agents, including former acting director Sullivan, expressed opinions that he would not be a good pick.
The ATF needs a permanent director, but not Chipman.
Fun fact: the building in which Grendel’s [and the Den] resides was a Harvard social club, long defunct. The park in front is where Jack Lemmon was once arrested for playing the piano naked and drunk, having removed said piano from said club for the performance.