Can a no contest plea under section 1203.4 of the California Penal Code be reduced to a charge of assault against an illegal immigrant?

In 2005, on appellant's motion under Penal Code section 1203.4, the superior court reduced appellant's conviction to a misdemeanor, and then set aside his plea and dismissed the case. This dismissal did not, however, eliminate the federal immigration consequences of the conviction. (See Ramirez-Castro v. I.N.S. (9th Cir. 2002) 287 F.3d 1172, 1174.) In July 2006, appellant filed the present motion, also styled a petition for writ of error coram nobis, to set aside his no contest plea and the judgment of conviction. Appellant argued that he had entered his plea 15 years earlier without knowledge of its consequences, and that his trial counsel had performed ineffectively.