A real Dingell-ing!!! I wouldn't blame dad for changing that name. Hard to get elected with a name no one can pronounce, regardless of anything else. He wouldn't have been the first Polish (or Italian, or Jewish, or whatever) American to Anglicize his or her name, nor the last. Nowadays, though, if your family name is Spanish-sounding, you'd be better off to keep it as it is.
You can get away with Dutch names in Michigan but that’s about as exotic as they get outside Detroit.