The salaries they make, the federal income and state taxes they pay in, and the resources they draw from housing, sending their kids to school, healthcare (we know that many will not have health insurance), housing, food stamps, and any other "assistance" they may need or get because they have kids. Many are paid in cash, so you know they are not cutting a check to Uncle Sam at the end of the year. No W2. The average undocumented worker makes about a 42 percent lower wage than natural born citizens. The average wage in 2019 in California for immigrants in general was $19 an hour, compared to $26 and hour for natural born citizens (google it). Considering that a good chunk of Americans are now paycheck to paycheck, you can easily see why migrants are a negative drain to us. Do we need some in farm work and things such as that? Sure! However, they are an overall burden. Simple math.
Individuals lacking legal status face obstacles that limit their job options and lower their productivity.
econofact.org