Some issues are frightfully stubborn. One such problem is xenophobia. In medieval Europe, people living two villages over were suspicious, never mind the people across the river who spoke a different language. In the USA the massive influx of German and Irish Catholics in the 1830's scared native Protestants, and a violent reaction set in, which formed the No Nothing Party, rabidly opposed to immigration and Catholicism. Irish Catholics themselves were viciously racist and sparked many racial riots, including the worst in the nation's history in NYC in 1863. After the war the KKK emerged as yet another hate group focusing on immigrants, Jews, and again Catholics. Lo and behold, evangelical Christians are at it again, claiming that Mexicans and Muslims are dire threats to racial purity and our nation's white heritage.