What caused Americans growing fear of radical political ideas?

Americans' growing fear of radical political ideas in the early 20th century was largely fueled by events such as the Russian Revolution of 1917, which intensified concerns about communism and socialism. The subsequent Red Scare, marked by widespread anti-communist sentiment and government crackdowns on perceived radicals, further amplified these fears. Additionally, social and economic instability following World War I, including labor strikes and Immigration, contributed to anxieties about the potential for revolutionary change in the United States. This combination of political upheaval and domestic unrest fostered a climate of suspicion and fear towards radical ideologies.