The opening paragraph for easy viewing:

Militant, nationalistic, white supremacist violent extremism has increased in the United States. In fact, the number of far-right attacks continues to outpace all other types of terrorism and domestic violent extremism. Since 1990, far-right extremists have committed far more ideologically motivated homicides than far-left or radical Islamist extremists, including 227 events that took more than 520 lives.[1] In this same period, far-left extremists committed 42 ideologically motivated attacks that took 78 lives.[2] A recent threat assessment by the U.S. Department of Homeland Security concluded that domestic violent extremists are an acute threat and highlighted a probability that COVID-19 pandemic-related stressors, long-standing ideological grievances related to immigration, and narratives surrounding electoral fraud will continue to serve as a justification for violent actions.[3]

So also: the right wing extremism is motivated by immigration ideology grievances and electoral fraud claims. Probably unrelated that an administration built on lies about immigration and electoral fraud wants this removed.