I would argue that for several decades now it has been the Republican Party that has been post-racial, or at least aspiring to that condition, while Democrats have been stubbornly working to preserve and increase racial antagonisms. This campaign has made that distinction impossible to avoid. Obama and his supporters constantly raise issues of race and imply that their opponents are racists, while the Republicans raise issues of individual character and, appropriately, avoid drawing distinctions on the basis of race.
It is Palin, not Obama supporters, who is post-racial.
I would further argue that this reflects deeper currents of thought that divide the two parties. Republicans tend to look at people as individuals with individual aspirations and responsibilities -- Democrats tend to view people as representatives of social science categories. This distinction between individualism and group think divides the parties on a wide range of issues and is fundamental to understanding the underlying themes of political discourse in this country.