Ga. Const. of 1983, Art. II, Sec. I, Par. II. "The object of the voter registration law `is to insure and sustain the integrity of public elections. . . .' [Cit.]" Johnson v. Byrd, 263 Ga. 173, 174 (2) ( 429 SE2d 923) (1993). "Registration laws are the means or machinery under which proofs are furnished showing the existence of the voter's qualifications.