The problem is that far-right extremism is by far the biggest violent threat, a multiple of Islamist extremism or far-left extremism. This applies not only to the US but most of Europe as well.
Feel free to check out any of the pieces below
https://www.economist.com/graphic-detail/2020/10/27/in-ameri...
https://www.nytimes.com/2020/10/24/us/domestic-terrorist-gro...
https://cco.ndu.edu/PRISM/PRISM-Volume-6-no-2/Article/839011...
https://www.europol.europa.eu/activities-services/main-repor... (p. 11)