Not every harmful ruling can be appealed. In the Georgia Court of Appeals, some types of cases can be heard only if the court first decides to accept them for review. In the Supreme Court of Georgia and the Supreme Court of the United States, that’s true of almost all criminal cases.
The lawyer’s first job in these cases is to persuade the court that a case is worth hearing, usually by showing that it presents an important legal question that should be answered to clarify the law. This can involve explaining how the issue has been decided in other states or in federal courts elsewhere in the United States. It can also mean proving that the case provides a good opportunity to discuss the legal issue and to give clear guidance to lower courts.
The court rules that apply to these applications (sometimes called petitions for certiorari) are somewhere between picky and downright oppressive. I have a lot of experience navigating those rules and a decent track record getting applications granted. It’s not just winning an appeal, but also getting through the courthouse door in the first place, that requires a skilled and experienced appellate lawyer.