Which statement explains why support for white supremacist groups increased during the 1920s?

The support for the white supremacist groups increased during the 1920s because wartime propaganda increased suspicion of people perceived as lacking in patriotism.

Explanation:

All the war propaganda during the 1920s was loaded with lots of patriotism and demanded citizens to respect and defend who they were as society, this opens the door to the supremacist groups exposing their point of view as a way to be patriotic and to keep their nation clean and free, the propaganda didn't only punish political opinions but also genetic heritage.

the lowest among the social higher rank were the working class. this class remained detached to the political progression   of the country and was hostile to the other two classes

abraham lincoln  (february 12, 1809  – april 15, 1865) was an american statesman, politician, and lawyer who served as the 16th  president of the united states  from 1861 until  his assassination  in april 1865. lincoln led the nation through the  american civil war, its bloodiest war and its greatest moral, constitutional, and political crisis.[2][3]  he preserved the  union,  abolished slavery, strengthened the  federal government, and modernized  the u.s. economy.