Lots has changed since the 2015 YouGov/Huffington Post poll, which suggested West had a potential audience in black Democrats. As he has become increasingly reactionary, and unpredictable, his popularity has waned. This is especially true amongst Democrats who view his praise of President Trump with suspicion.
More recent polls suggest that West is very unpopular with Democrat voters. A 2018 CNN poll found that 12% of Democrats viewed him favourably, compared to 67% who were unimpressed. Meanwhile, Republicans were evenly split at 35% to 35%.