Sentence:  ... there was no sympathy and connection between the upper and the lower people of the Irish. To one who had been bred so much abroad as myself, this difference between Catholic and Protestant was doubly striking; and though as firm as a rock in my own faith, yet I could not help remembering my grandfather held a different one, and wondering that there should be such a political difference between the two. I passed among my neighbours for a dangerous <WSD>leveller</WSD>, for entertaining and expressing such opinions ... 
Meaning of the word marked with <WSD> tags:  A person holding a political opinion in favor of eliminating disparities between the haves and the have nots.