I believe the "B" stands for, "Spreading The Wealth", ...
... to bad the attacker couldn't wait untill after the election.
Of course, the lady could have made the story up, and carved the "B" into her face herself, ...
... that's the first thing I thought of when I heard this, - and that is the first thing I thought of when a black college prof. had a noose hung on her front door, ...
... she probable put it there herself.
That's just the way I think.