What does the saying ''don't change horses in midstream'' mean?

Answer 1

This is a common political quotation used by political campaigners in the United States as a reference to a continuation of stability in policy stance or political party affiliation. It has taken on proverbial status as a way to distinguish oneself as upright and dependable in political position rather than the "waffling" or change of position of one's opponent. In this way, it is used to gain political advantage over one's opponent by appearing more trustworthy than him or her.

It is also sometimes is used by incumbent campaigners to voice their opinion that the voter should vote for them again, because of the satisfactory job the incumbent did during the term, playing on the unknown nature of a challenger to the position, in order to convince voters to keep the incumbent in office to continue the satisfactory job. A similar reference, though much more cynical, is the well known phrase "better the devil you know, than the devil you don't," dating back to the 1500's.

The original usage of "don't change horses in midstream" is attributed to Abraham Lincoln during a speech in 1864.