Answer:
By the year 1960, the Civil Rights Movement had obtained a great audience. Thanks to Martin Luther King Jr and his admirable efforts to advocate non violence, African American activists around the globe were able to gain a widespread support.
I'd like to think it adds a tone of disgust. "Horrible vermin", as in "gross creature."
The Emperor Wu of Han received reports of the tall and powerful horses ("heavenly horses") in the possession of the Dayuan, which were of capital importance to fight the nomad Xiongnu. The refusal of the Dayuan to offer them enough horses along with a series of conflicts and mutual disrespect resulted in the death of the Chinese ambassador and the confiscation of the gold sent as payment for the horses.
