This article in Salon is worth reading, especially the links. It points out the following, for those seeking a summary:
1. From 1877 to 1950, nearly 4,000 individuals were the victims of lynchings. Some have speculated that as many as 75% of historical lynchings "were perpetrated with the direct or indirect assistance of law enforcement personnel." Despite drawing attention from large crowds, many perpetrators of historical lynchings were never charged with a crime — a fact seen in many modern-day officer-involved shootings.
2. In comparing "historical lynchings and present-day officer-involved shootings," the researchers concluded that "historical lynchings are positively associated with officer-involved shootings for Blacks. That is, counties that experienced a higher number of historical lynchings have larger shares of officer-involved shootings of Blacks in the last five years."
3. Political scientists have shown that Southern counties which had a Ku Klux Klan chapter in the 1960s were more likely to abandon the Democratic Party and become Republican. This shift in party allegiance came in large part in response to the Democratic Party's support of the civil rights movement. A 2016 article in the Journal of Politics shows that white Southerners who live in counties where the enslavement of Black people was prevalent are now more likely to be conservative, vote Republican and possess hostile attitudes towards Black people, compared to white people who live in counties where slavery was not as common.
4. A 2016 YouGov/Economist public opinion poll suggested that 20 percent of Trump supporters believe that Black people should still be slaves. Deplorable, right? Really. Right?
The entire article is worth the read, including the personal thoughts of an African-American woman quoted near the start of the article, noting it is not her blackness which should be a cause for worry and despair, but racism. The end has thoughts from a white southerner who is a modern novelist, who captures my very thoughts about the topic of the Confederate (really Northern Virginia army) flag and the Confederate generals' and presidents' monuments erected at the end of the 19th Century and early 20th Century to re-enforce white supermacy.