There Are No Anchor Babies
And even if some immigrants were trying to have anchor babies, their plan would fail. Anchor babies simply do not work well enough to be a reasonable strategy. There are basically two routes under current US immigration law for someone to get status on the basis of having a US citizen child:
A. Petitioning: A US citizen can petition for a close relative to be granted status. This is probably what people who fear "anchor babies" are thinking of. The trick here is that the child can't petition for anyone until they're 21 years old. And even after the petition is filed, it could take several more years to process the application, depending on the complexity of the case, the number of waivers needed (at minimum, the mother would need a waiver for their unlawful presence at the time of the child's birth), and the number of appeals. So petitioning requires a possibly 25-year wait and is not guarantee of getting status at the end. In the meantime, this route may be cut off -- many right-wing and centrist immigration reform proposals, one of which could become law in the next 21 years, propose streamlining the hugely inefficient and backlogged family immigration system by limiting people to petitioning for spouses and minor children only.
B. 10-year cancellation: Current immigration law provides that someone can get a green card if they:
1. Have been continuously in the US for 10 years,
2. Have "good moral character,"
3. Have a parent or child with status who would suffer hardship from them being deported.
All three of these criteria are hard to meet under current case law. If you're undocumented and living in the shadows, it will be tough to produce evidence that proves that you were in the US for ten years even if you've managed to evade ICE and forgo visiting family in your home country long enough to actually accomplish it. "Good moral character" is subject to a variety of statutory bars -- you can't have criminal convictions, fake papers, etc. -- as well as also being subject to denial on the judge's discretion if they don't like you. Finally, "hardship" in practice means "your parent or child is deathly ill." It would take a pretty twisted mind to have a child hoping that in 10 years they'll be sick enough that you can get 10-year cancellation. What this all adds up to is that practually no-one ever actually gets 10-year cancellation. Of the dozens of people in the Florence immigration court over the last three years who have been prima facie eligible to apply for 10-year cancellation, exactly three have had it granted by the judge -- two of whom have had it overturned by the Board of Immigration Appeals, while the third has an appeal pending before the BIA.