In what ways are his ideas reflected in the history of democracy ?

Henry David Thoreau is famous for his essay on civil disobedience. In what ways are his ideas reflected in the history of democracy ? Who borrowed from his thinking later? Are there any flaws in his reasoning or approach? What role does civil disobedience play in a democracy? Are there limits? Can violence ever be justified as a form of civil disobedience? What forms of civil disobedience do we see today? Are they a positive or negative factor in our society?