Well, playing the "China threat" card to enhance domestic unity definitely work, as least for now. However, give the fact that folks who refuse to be vaccinated are in the process of contributing to the third COVID wave in the United States, I don't know how long this "anti-China" unity we see right now could be sustained, especially if the economy does not pick up in the next 2-3 years. Also, Wall Street and major US firms have vested interests (including a number of US defense contractors like Boeing) in sustaining trade with China, so a significant number of big monies in America do not want to see a full unraveling of US-China Relations. As Secretary of State Blinken said, Washington hopes to engage China from a position of strength, but currently it does not have it (and COVID-induced economic woes, along with those who refuse to be vaccinated or spread conspiracy theories, are not helping).Yes, that is the problem
Anti-China rethoric is one of the best glue that sticks Americans together, without " common enemy " they will devide.
Trump knew that, now Biden is aware too.