You cannot try someone in a state court for a federal crime.
Many offenses are only punishable in federal court, and vice versa. But Bugliosi does seem to lay out a case in his book on how state courts can have jurisdiction.
Also, a pardon is a pardon. The states couldn't touch him.
Wrong! The Rodney King beaters were found not guilty in State court but were found guilty in federal court because both it was both a state and federal crime. You can't be tried twice in the same jurisidction, otherwise this would be double jeapordy.
Because state law is seperate from federal law, the President cannot be pardoned. A pardon is an executive order to a US attorney, federal agent, etc not to arrest, indict, or seize assets of an individual under federal jurisdiction. IF SOMEONE IS FOUND GUILTY IN BOTH FEDERAL AND STATE COURTS, A PRESIDENT PARDON WOULD ONLY GET THEM OUT OF THE FEDERAL CONVICTION.