=What the Leading Political Parties Stand for.=—The general ideas upon which the members of a political party agree are incorporated into its platform and are commonly known as the party’s _principles_. For example, a party may pledge itself to the principle of promoting foreign trade, or conserving the natural resources of the country, or keeping aloof from the affairs of Europe. The methods by which these principles are to be carried into effect constitute the party’s _policy_. The principle of promoting foreign trade, to take an example, may be carried into effect by lending money or credit to exporters, as was done after the World War. But the different parties do not usually agree upon either principles or policy, and this divergence gives rise to party _issues_ or points of conflict between the parties. It is not easy to set forth in concise form the principal issues. During the campaign of 1916 the attitude of the United States towards the great European conflict was the pivot of attention; in 1920 the question whether America should or should not enter the League of Nations crowded most of the other issues into the background. The main planks in party platform change from one election to another.[52] During the past twenty years the platforms of both parties have dealt with a wide variety of matters; but the disagreement between the two parties has not always been clean-cut and in some cases it has left the voter little to choose between them. On some matters the two leading platforms are openly opposed; on others they are very much alike, and on some others, again, they are so ambiguous that it is difficult to tell just where they differ. As a practical matter it is not always wise to take an absolutely definite stand in the party platform, for conditions may change and by so doing place the party in the position of having pledged something which ought not, in view of the changed conditions, to be carried out. =The Minor Parties.=—Americans, on the whole, have accepted the two-party system. The great majority of voters are either Republicans or Democrats. Nevertheless the platforms of these two parties never suit all the people and the result is that minor parties, or “third” parties as they are sometimes called, come into existence from time to time. During the past hundred years a dozen or more of these minor parties have been formed but with two or three exceptions they have soon melted away.[53] These exceptions are the Prohibition party, which was organized in 1872 for the purpose of securing the complete suppression of the liquor traffic in the United States. The adoption of the Eighteenth Amendment gave this party the chief thing that it had been contending for, but it has not yet gone out of existence. The Socialist party is the other example of a “third party” which has continued to be active for a considerable period. [Sidenote: Why “third parties” rarely survive.]