Left wing extremist is not a term that exists in their lexicon.
The actions of John Lindh were excused as the actions of a young man on a spiritual quest.
The treasonous slander from John Kerry to Congress during the Vietnam war was later called the words of an angry young man (not treason).
The New York Times championed William Ayers (and thousands of professors signed a protest in his support).
Radical Chic still exists among liberal intelligentsia.