During the 2020 campaign, candidate Joe Biden promised to undo President Donald Trump's border security policies. He pledged to halt all deportations for 100 days and allow asylum seekers who enter the United States illegally to stay in this country while their cases are considered, rather than wait in Mexico, as Trump required. It was obvious that Biden's changes would attract a flood of new illegal immigrants. So during the transition, the president-elect tried to lower expectations. In late December, Biden told reporters he would not throw out the Trump program immediately, lest the United States "end up with 2...