From the BBC on the subject of David Patraeus potentially replacing Michael Flynn as National Security Adviser:
Once considered a rising star in the Republican Party after his success organising the 2007 US military troop “surge” in Iraq, he was forced to resign from the CIA in disgrace and charged with sharing top secret documents with a civilian reporter with whom he was having an extra-marital affair. He eventually pleaded guilty to mishandling classified information
That, it seems, has not been a career-killing event, however.
Didn’t Hillary running for President prove beyond all doubt that mishandling classified information isn’t a career-killer? Although granted, had she not been called Clinton it might have been. That name provides ample cover for extra-marital affairs, too.