The Trump transition team was already considering candidates for a host of Defense Department top jobs when Trump announced Dec. 1 that he intended to nominate "Mad Dog" Mattis to lead the military. The Mattis pick was seen by Republicans around Washington as an indication that Trump would rely on senior and experienced officials to shape and implement his national security and foreign policies. Many "Never Trump" Republicans also thought this might be their way into service despite having opposed Trump in the GOP primary.