Because they do:
Even presidential pets were viewed through the same lens. Tesler showed 1,000 YouGov respondents a picture of a Portuguese water dog and asked how favorably they felt toward it. Half saw the dog introduced as Bo Obama, and half as Ted Kennedy’s dog, Splash. (Both political dogs are the same breed, but the picture was of Obama’s.) Those with negative feelings toward blacks thought less of Obama’s dog.The bigots can't even keep their racial animus from infecting their view of a pet.