A statehouse is not a watering hole and referencing blood libel is just a bad move.
It's a bad move only because the Press and the Professionally Aggrieved will misrepresent it. The statement is, in fact, accurate. The current government of the Commonwealth of Virginia is no more responsible for plantation slavery than any currently alive Jews are responsible for the Crucifixion. Less, in fact; if you are a Christian, you'll agree that ALL of us bear some 'responsibility' for Christ's sacrificial death.
He referenced the blood libel to point out the absurdity of it.
Anyone offended by that part of his remarks is either dumb or just reading headlines.