For all the stuttering Joe Biden is known for, he sure could say "nigger" without any sort of complication in 1985; perhaps now, amidst rumors that Biden is suffering from dementia and not of a fit mind, his ability to say "nigger" will double as a sign that we have the old Joe back.
Source: http://www.c-span.org/video/?c4854577/user-clip-1985-hearing-joe-biden-word
Source: http://www.c-span.org/video/?c4854577/user-clip-1985-hearing-joe-biden-word