None of this rhetoric about a Chinese “invasion” or “threat” is new. There is a long history of anti-Chinese and anti-Asian rhetoric in the United States. In the past, such rhetoric has led to violence and discrimination. Using it now—despite the lack of evidence that China or the CCP is using the border to "infiltrate" the country—threatens to stoke backlash against Chinese migrants and Asian Americans, as well as further damage the U.S. diplomatic relationship with China.
Much of the early structure for policing U.S. borders and restricting immigration originated with a movement to restrict the arrival of Chinese laborers. In the 1870s, the growing number of Chinese immigrants entering the United States to earn money, working first in gold mining and then laying new railroads, faced increasing opposition from white workers concerned about competition driving down their own wages and working conditions.
Despite the relatively small numbers of Chinese immigrants, rhetoric focused on the effects of a Chinese “invasion” as well as a global narrative of a “yellow peril” that could result in Western countries being overrun by Chinese migrants intent on fundamentally transforming their cultures.
This rhetoric gave rise to the anti-Chinese movement in the American West, which translated into violent uprisings, shootings, and efforts to drive Chinese residents out of towns where they lived.
It also resulted in the federal Chinese Exclusion Acts, the first of which passed in 1882 to temporarily restrict the arrival of Chinese laborers. The measure was eventually made permanent by 1904, singling out the Chinese as the only people to be barred from entry on the basis of race, beyond admitting temporary residents on specific business, like diplomats, merchants, and students.
The Acts led to a decrease in the population of Chinese migrants already in the United States and prevented migrants from returning if they left to visit family in China. The Acts also stated that Chinese people could also not become naturalized American citizens, ensuring that those living in the U.S. would be cast as perpetual foreigners.
It was only during the Second World War that American impressions of the Chinese people gradually improved, when China was the “first to fight” against the Axis powers after the Japanese invasion. As a part of a larger series of measures aimed to aid China’s morale as a U.S. ally, the U.S. Congress repealed the Chinese Exclusion Act in 1943. For a brief period, Chinese immigrants to the United States were celebrated, though only accepted in small numbers thanks to the national origin quotas system put in place in the 1920s that curbed immigration from nearly everywhere but countries in Northwest Europe such as the United Kingdom.