Most (all?) states will also offer pro hac vice, meaning the lawyer can temporarily practice in that case only, typically after applying by way of motion, payin

Most (all?) states will also offer pro hac vice, meaning the lawyer can temporarily practice in that case only, typically after applying by way of motion, paying a fee (usually a couple hundred dollars or so) and having an associated local counsel, who is supposed to advise on local legal matters and oversee the foreign attorney (but often does neither). Courts in many states will start rejecting pro hac requests as they approach the line of abuse, so the attorney will need to become a member of the state's bar. While pro hac, the attorney generally will have at least the same ethical and competency obligations as any attorney regularly admitted to that state's bar.