Vermont Sen. Bernie Sanders, who attended Pope Francis' address to Congress this morning in Washington, D.C., was thrilled by one of the "four representatives of the American people" brought up in his holiness' speech:

Three sons and a daughter of this land, four individuals and four dreams: Lincoln, liberty; Martin Luther King, liberty in plurality and non-exclusion; Dorothy Day, social justice and the rights of persons; and Thomas Merton, the capacity for dialogue and openness to God. [Pope Francis, via Vox]

It wasn't Lincoln, King, or Merton who got Sanders grinning — it was Dorothy Day.

"The name Dorothy Day has not been used in the United States Congress terribly often," Sanders told The Washington Post. "She was a valiant fighter for workers, was very strong in her belief for social justice, and I think it was extraordinary that he cited her as one of the most important people in recent American history. This would be one of the very, very few times that somebody as radical as Dorothy Day was mentioned."

Day, a journalist who advocated for pacifism, women's rights, and social justice, is a controversial figure in some circles due to her radicalism, especially because she also had an abortion in the early years of her life. Others, meanwhile, have pushed for her sainthood.

"[The Pope] knew where he was speaking," Sanders said. "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." Jeva Lange