What "Muslim smear"?  

 St. Bakhita was a indeed a slave of Muslims, and the Pope himself described St. Bakhita as a "young woman who was enslaved in Africa, exploited, humiliated," Pope Francis said she never gave up hope.   Being a slave and being "exploited, humiliated"  (we know what that means)  and forced to convert to Islam sounds like cruel persecution to me.