Because of racism, some people will call themselves "Cajun" when they are actually Creole.

"Cajunism operates on a Canadian and French identity; many Louisianians who have no Canadian ancestry will dig hard to find one to validate their Cajunité, too. When the genealogy proves unsuccessful, they parade around claiming to be “culturally” Cajun, anything to avoid being Creole. In their minds, Canada and France are where Whites live and come from, which makes Cajun an implicitly white ethno-racial identity." - "That leaves the remaining “Francophones” in Louisiana to continue identifying as Creoles (or, French Creoles, Spanish Creoles, or Black Creoles), making Creole, therefore, an explicitly black/mixed/other ethnic identity. Still, some Whites, in disgust, will whisper to you: "We used to call ourselves Creoles before this Cajun stuff” - or “They call themselves Cajuns, but they're all Creoles." - Christophe Landry -

http://christophelandry.com/2011/07/19/cajun-or-creole-whats-in-a-name/