Often politicians in both parties think the smart move is to avoid principles that might be inconvenient in order to win an election. Abraham Lincoln disagreed with that idea and believed that principles were important to winning elections. Here is what he said to a victory rally of Chicago Republicans on the night of March 1, 1859:
"All you have to do is to keep the faith, to remain steadfast to the right, to stand by your banner. Nothing should lead you to leave your guns. Stand together, ready, with match in hand. Allow nothing to turn you to the right or to the left. Remember how long you have been in setting out on the true course; how long you have been in getting your neighbors to understand and believe as you now do. Stand by your principles; stand by your guns; and victory complete and permanent is sure at the last."
Source: Collected writings of Abraham Lincoln, Volume 3 on digital file at the University of Michigan.