Even though through our media, you'd think differently, but there's only a small faction (...../National Socialist-types) that care that our President is black, other than the people who voted for him for that reason alone. More care about what his policies are, rather than his skin color. Same with a possible woman president, or a Hispanic. If it ends up that Marco Rubio or Ted Cruz is President, there will be no mention in the major news media about their race - it will be all about their politics. If there is criticism, Fox News, for example, will not make the point (as main stream media has done with Obama) that race is a factor.
And... not much of what Obama has been 'derailed'. As far as transforming America, he's been pretty successful. His main advisor, Valerie Jarrett, who some say is the real President, has done a stellar job in bringing that about.