karl rove has been teflon so far. criminal allegations swirl around him all the time, but none ever seem to stick. they probably won't this time either. but there still is an actual possibility that criminal charges might stick this time.
less cryptic version: the republican national committee used to delete all its emails after 30 days, whereas white house emails are required by law to be preserved for posterity. as a result rove and other white house insiders started using RNC email addresses for business. in 2004, patrick fitzgerald told the RNC to stop deleting the emails. the RNC did, except that rove continued delete his emails even though they were on the RNC server. deleting emails after you are told not to by a federal prosecutor who is investigating you is obstruction of justice.