If Obama visits Arizona again, Sheriff Joe should just go arrest him. Since Obama is a fraud, there’s no Constitutional reason why he cannot be arrested.
Some may consider it an open question as to whether the Constitution would allow the president to be arrested and tried and convicted in a state court for the state (not federal) crimes of forgery and electoral fraud.
In Clinton v Jones, the president was sued in a civil case by a private party (Paula Jones) under both federal and state law and the Supreme Court held that the private party was not required to wait until the president was out of office before proceeding with the lawsuit.
Nevertheless, in the case of crimes, I would expect the courts to rule that "high crimes and misdemeanors" encompasses both federal and state crimes and that the president must be impeached and removed by the House and Senate before he may be tried and convicted of a serious crime in a state court.