#1) How are they similar to "the slaves of political parties"?
Answer: Slaves wanted to be trusted by their overseers because this often would grant them privileges that other slaves did not have.
#2) Why does Douglass make this comparison?
Answer: Slaves would seek with great care to please their overseers to gain their trust, just as office-seekers in the political parties seek to please and deceive the people.
I hope it helps, Regards.
<span>Keeping this definition in mind, most of the lines in the prologue alude to the fact that the play will be a tragedy. It talks about how civil blood will make civil hands unclean, how two star-crossed lovers will take their own lives, and how their deaths will end a long-term dispute between two respectable families.</span>