No one can say for certain how big a role these high levels of illegal immigration have played in the spread of the virus, but the Biden administration can’t have it both ways. If the president wants the public to defer to public-health officials when it comes to masking and social distancing, he can’t expect people to ignore these same officials when they tell us that large numbers of recent migrants may be contributing to the crisis.

Team Biden insists that the problem is driven by forces beyond their control, which is a dodge. Last week, Vice President Kamala Harris released a 14-page plan for addressing the “root causes” of illegal immigration, citing high rates of violence and poverty in countries like El Salvador, Guatemala and Honduras, which have become large sources of illegal immigration to the U.S. Collaborating with other governments is smart and necessary, but it’s insufficient. Violent crime, high unemployment and widespread poverty back home all play a role in sending people north, but so does lax U.S. border security and an unwillingness to enforce our laws.

El Salvador’s homicide rate fell by more than half between 2015 and 2018, and Guatemala’s economy was averaging 3.4% growth in the years leading up to the pandemic. Both countries continue to be much poorer and more violent than ours, but it’s worth noting that emigration to the U.S. from Central America kept rising even as these “root cause” trends moved in the right direction.