“Any use of emotion (whether it be fear, patriotism, love, guilt, or any of the others in the pantheon of feelings) that is designed to sway your opinion is manipulation.”
When someone attempts to prey upon your guilt over having “too much,” your fear of another “terror attack,” your anger over “the rich” making a killing at your expense, or your fear of being labeled a “racist” or of being ostracized from the “cool” crowd… they are manipulating you. Their arguments are weak; because they cannot appeal to you through logic, they go through the less heavily-guarded back door of emotions. Beware.