Day was arguably the least famous of the four Americans Francis cited in the speech, but she was a vital and controversial figure on the American left. Like Martin Luther King -- also cited by Francis -- she had a thick FBI file, compiled by agents tracking her support for democratic socialism and opposition to foreign wars. "We need to change the system," Day wrote in 1956. "We need to overthrow, not the government, as the authorities are always accusing the Communists 'of conspiring to teach [us] to do,' but this rotten, decadent, putrid industrial capitalist system which breeds such suffering in the whited sepulcher of New York."
Recent support for Day's possible canonization has angered some conservatives. "Vatican archives are filled with reports of Christians martyred under the regimes that Dorothy Day supported," wrote Virginia State Senator Dick Black in a 2013 letter to Francis's predecessor, Pope Benedict. "I am revolted by the United States Conference of Catholic Bishops’ support for the canonization of a woman whose views supported the violent extermination of Christians throughout the world."
Sanders, well aware of Day's views and her critics, considered it bold and telling that Francis would praise her. "He is willing to identify with an extraordinarily courageous woman whose life was about standing with the poorest people in America, and having the courage to stand up to the very powerful," he said. "You know, her newspaper was the Catholic Worker, and she stood with the workers of America and fought for justice."
The Vermont senator was less concerned by Francis's glancing mentions of other issues that animate progressives, such as climate change and gay rights. "He knew where he was speaking," said Sanders. "I think he does not want to be rude, as a guest. But I think his calling out for social justice, his talking about income and wealth inequality, his talking about creating an economy and a culture that works for everybody, not just a few, is a very, very powerful message."