Biden has pledged to reverse many of the hardline immigration policies of former Pres. Trump, but has struggled with record-high attempted border crossings. His unwise rollback of these policies has encouraged even more illegal immigration and has led to the current crisis.
Although Biden is often blamed for the current migration numbers, the majority of the crossings happened under Trump-era policies. Title 42 was intended to deter migration into the U.S. during the COVID pandemic, but it has created a crisis instead. This situation was incubated under Trump's initiatives and ideology.
The pandemic hit Latin American economies harder than any other region in the world, forcing millions of people out of work, while in the U.S. the post-COVID rebound created a strong demand for the kinds of low-paying jobs migrants usually take. This is not a political issue but rather a matter of global supply and demand for labor.