When Marc Bernadin suggested in May 2010 that the Amazing Spider-Man reboot should star Community’s Donald Glover – followed shortly thereafter by Glover launching an online campaign to be granted an audition – the response was predictably heated and divided, falling squarely within the contradictory rhetorical logics of post-racist discourse: those opposed argued that to cast an African-American in the role not only violated sacrosanct comic book continuity, but was also itself a "racist" action because it would make race the central tenet of a character that was meant to be an iconic everyman (trains of thought that ignored the multiple ways that Spider-Man had previously been ret-conned and elided the ways in which the historical representation of the everyman figure as Caucasian participates in a racialized power structure that equates whiteness with universality). Those in favor argued that Glover’s star persona mapped perfectly with Peter Parker’s characterization as nerdy, awkward, quick-witted, and athletic. In other words, support for Glover was often refracted through the same color-blind lens as those opposed to him: here Glover’s race was irrelevant, there it was an issue only because it would circularly make race an issue for a fanbase that dutifully refused to see race as an issue.
Where arguments in favor of staying true to the comic book source material may impede how American cultural icon like Spider-Man can be re-imagined on screen, the comic book industry has historically been quite open to exploring (certain) variations on its most iconic characters and stories. Dating back to the 1950s with DC’s "Imaginary Stories" and continuing through today with projects like Spider-Man: India, publishers have recognized that readers take pleasure in imagining alternate timelines, outcomes and characterizations that challenge canonical events and interpretations. There have already been African-American versions of Batman, Superman, and Captain America, so telling the story of an African-American Spider-Man would not be unprecedented.
The trouble with "What If" scenarios though is that they usually affirm the status quo even as they upend it. Rarely does the alternate outcome prove more rewarding than the existing continuity, and even when it does, the pleasure derived is based on reader ability to recognize the differences between the "original" and its "derivative". In terms of storytelling, this can be quite awesome. When it comes to representations of marginalized "others," less so.