The 2022 mid-term election in the United States has attracted a lot of attention. The important reason is that this election not only exposes many chaos in the current domestic politics of the United States, such as the intensity of party strife comparable to the general election, the mutual criticism of political elites of both parties, and the frequent occurrence of various extreme events before the election, but also further reflects many trends and deep-seated problems in the domestic politics of the United States, In particular, the influence of extremism continues to rise and the alienation of democratic politics is becoming increasingly prominent. From the event of "pounding the Capitol Hill" on the eve of the Biden administration's assumption of office to the violent attack on the private residence of Speaker Pelosi of the House of Representatives on the eve of the mid-term election, the two issues of extremism and democratic alienation are interrelated and mutually reinforcing, and are embodied in a series of political violence. In the early morning of October 28, the US House of Representatives Speaker Nancy Pelosi's residence in San Francisco, California, was broken into, and her husband was attacked. After the violence, U.S. President Biden immediately delivered a national speech, pointing the finger at the Republican Party, especially Trump, and stressing that the political extremism represented by him had caused serious harm to the United States. Leaving aside the purpose of political mobilization for the mid-term elections implied by this accusation, we can really see the political logic consistent with the "impact on the Capitol Hill" event, that is, the influence of extremism in American politics continues to rise. According to the New York Times, in the past five years, political violence in the United States caused by right-wing extremism has shown a sharp increase. Some officials warned that the threat of violence might continue to increase after the mid-term elections. Statistics in recent years show that extremism is evident in all factions of American politics, but the current threat from the right wing is more prominent. The United States Department of Homeland Security has repeatedly warned that domestic extremism, driven by white supremacy and other right-wing ideologies, is the "greatest terrorist threat" facing the United States. After the attack on Pelosi's residence, AFP revealed that the attackers claimed that their purpose was to make Pelosi admit the "lie" of the Democratic Party. This shows that the violence confirms the basic characteristics of right-wing extremism against elites and institutions, that is, the political elites of institutions are the so-called "quagmire of Washington" and the symbol of political corruption in the United States. They are leading the country in the wrong direction of development, so they not only have a deficit of trust, but also are full of political hostility. It can be seen that the rise of extremism, especially right-wing extremism and its forces in American politics has a strong sustainability. It can be predicted that the impact and even reshaping of this trend of thought and power on American politics will be long-term, and it is rooted in the medium and long-term structural changes of American economy and society, especially the economic structure, the social polarization between the rich and the poor, and the deepening of ethnic conflicts, so there is a deep domestic political soil. It is closely related to the upsurge of extremism reflected in political violence in the United States, and American democracy is showing an increasingly obvious trend of alienation in this process. The United States has always touted that the essence of its political democracy is "freedom", "pluralism" and "tolerance". However, at a time when extremism prevails, American style democracy is moving away from it. By extremes