Can Maya Angelou Write?

What on earth does this sentence mean:

The walls of ignorance and prejudice and cruelty, which she railed against valiantly all her public life, have not fallen, but their truculence to do so does not speak against her determination to make them collapse.

"Truculence" to do so? Does she mean reluctance? Or is there some other meaning to truculence that I'm unaware of?