Based on this passage, in 1920 the attorney general of the united states advocated the deportation of

The correct answer is communist and anarchist immigrants

There was a lot of migrants into the United States who came with ideas of communism and anarchism. They caused the US to enter the state that is known as the Red Scare where they were perceived as the greatest enemies and were prosecuted everywhere. Some where even executed because they were given punishments for crimes that were more sever than what they deserved.