Liaison and Party Harmony: In the primary campaign your opposition is Jack Hopeful, a member of your own party. Never forget that you will need the support of all your party after the primary and never let your supporters forget it!

This is a very touchy, difficult matter, particularly in a volunteer organization. You are certain to have loyal supporters who are simple souls, unable to think in terms other than black and white. To them Jack Hopeful is the ENEMY - they will commit excesses through misguided zeal. So also will some of Mr. Hopeful’s supporters. Bad blood breeds more bad blood; in short order you can have a situation which is completely out of hand, which splits the party wide open, and which will render it impossible for your man to win in the finals.

Since the nomination is valueless in itself, being merely a necessary means to an end, you must prevent this at all costs.

–Robert A. Heinlein, Take Back Your Government