Why was there a rise of nativism in the 1920's

Nativism was the resistance toward immigrants and people of other countries. For one, soldiers coming back from the war came back to find that other people had taken their jobs, including blacks, and others from different countries that had immigrated here. Also, with the Sacco and Vanzetti trial, people didn't like immigrants because of their beliefs. Sacco and Vanzetti were Italian and people believed they were anarchists who were set on destroying the government, and just getting out of the war, Americans felt much patriotism and wanted to protect their country.