In chapter 42 of Anna Sewell's Black Beauty, Polly comes into the stable yard to inform Jerry that a politician named Mr. B-- has asked for Jerry's vote and "wants to hire [Jerry's] cab for the election." Jerry answers immediately and says he is unavailable. He further explains that it is an insult to Beauty, called Jack at this point, and Captain to "race about to the public-houses" picking up "half-drunken voters" and taking them to the polls. In other words, in Jerry's mind, voters have a tendency to behave unethically, and having the horses cater to their whims would be insulting to the horses and his driving business.
Jerry further explains that, though Mr. B-- is of Jerry's political party, he will not vote for him because Jerry thinks Mr. B--'s trade prevents him from actually knowing "what working men want"; Jerry, therefore, cannot in good conscience have the man making laws in the name of the working man.
Later in the chapter, when his daughter Dolly is attacked by boys of a different political party and Harry defends her, Jerry supports Harry for having defended his sister but warns him against hypocritical political prejudices. In Jerry's mind, people of political party affiliations have a tendency to be blind, prejudiced against others not of their party, and to vote on issues they only have half of an understanding of. Therefore, it is hypocritical for any of Jerry's family members to be equally prejudiced of people of different political affiliations. In Jerry's mind, all people should take elections very seriously and feel free to vote as their consciences tell them to vote, which are not actions Jerry sees people performing during elections. Therefore, he will not associate himself with elections.