O.C.G.A. § 21-2-522: Grounds for contest.

A result of a primary or election may be contested on one or more of the following grounds:

(1) Misconduct, fraud, or irregularity by any primary or election official or officials sufficient to change or place in doubt the result;

(2) When the defendant is ineligible for the nomination or office in dispute;

(3) When illegal votes have been received or legal votes rejected at the polls sufficient to change or place in doubt the result;

(4) For any error in counting the votes or declaring the result of the primary or election, if such error would change the result; or

(5) For any other cause which shows that another was the person legally nominated, elected, or eligible to compete in a run-off primary or election.