Dominica has a two-party system, which means that there are two dominant political parties, with extreme difficulty for anybody to achieve electoral success under the banner of any other party.
Matthias Catón: "Dominica" in: Elections in the Americas. A Data Handbook, vol. 1, ed. by Dieter Nohlen. Oxford University Press, Oxford, 2005: pp. 223–237 ISBN0-19-928357-5