In any party system, it would seem of some importance to establish rules and qualifications for membership in the different party groups, in order to bring together those persons, and only those persons, who adhere to the respective party principles. That should be particularly important in a two-party system, where the principles and issues are presumably sharply defined and clearly distinguishable. This matter has received increasing attention during recent years, and the importance of the problem was well stated by the Chicago Tribune, in an editorial referring to the Illinois primary campaign of 1938:
“The advantages of party organization and party responsibility have been proved over a long range of political testing, and although the abuses at times seem substantial. If a party is to be recognized as having legal standing, and if it is to make its nominations under the direction of law, there should be, it would seem, some determined qualification of its voters…. There shouldn't be a pretence of one thing and a fact of another. If Democrats and Republicans are to have legal standing as such, then Democrats should not make Republican decisions and Republicans should not make Democratic decisions. To permit this is to commit a fraud against the citizens who are trying to make their organization and their decisions according to the prevailing theory of political action and party responsibility.”