One way of holding together such a disparate coalition is by delivering prosperity, so that everyone can feel he's doing well. Failing that, another way is by identifying a common adversary--such as the "white male." During Obama's first term, the demonization of the "white male" was common among left-liberal commentators, especially MSNBC types. The Post has now lent its considerably more mainstream institutional voice to this form of bigotry.
Of course, demonization isn't limited to white males via slanderous claims of racism. Demonization is the standard campaign tactic used against anyone they oppose.