David Leonard, chair of Washington State University's department of critical culture, gender, and race studies, explained it this way in his 2012 Huffington Post essay, "Just Say No To blackface: Neo Minstrelsy and the Power to Dehumanize":
Blackface is part of a history of dehumanization, of denied citizenship, and of efforts to excuse and justify state violence. From lynchings to mass incarceration, whites have utilized blackface (and the resulting dehumanization) as part of its moral and legal justification for violence. It is time to stop with the dismissive arguments those that describe these offensive acts as pranks, ignorance and youthful indiscretions. Blackface is never a neutral form of entertainment, but an incredibly loaded site for the production of damaging stereotypes...the same stereotypes that undergird individual and state violence, American racism, and a centuries worth of injustice.