This article from 2016 reads like it could have been written today.
By Jesse Rhodes, Scientific American
The 2016 American presidential campaign has renewed concerns about the specter of violence in American electoral politics. The campaign has been marked by tense—and occasionally violent—altercations between supporters and critics of Republican nominee Donald Trump.
By refusing to commit to accepting the results of the election, he has confirmed the doubts among his supporters about the integrity of American elections. Thereby, he has increased the risk of possibly violent resistance by hard-core Trumpists.
It would be comforting to conclude that the menace of violence surrounding the 2016 presidential election is unique. But my research on the history of voting rights in the United States suggests that this is far from the case. Indeed, the threat and execution of violence around elections has a long, sad history in American politics.