Why do we only see Dem politicians and staffers referencing communists/racists in speeches?

Obama staffers referencing Mao, the Mao Ornament on the white-house tree, Maxine Waters praise of Castro, Hillary claiming Margret Sanger as her type of progressive. The communist party even had a booth at the last DNC sanctioned event on the mall. Is this an unholy union? or are democrats cool with this? Why only Dem's?