The Washington Post called out “the myth of the 'anchor baby'” for being a “largely a mythical idea” with little basis in the law.

On August 17, Donald Trump released the details of his immigration plan, which calls for Mexico to pay for the construction of a wall along the U.S.-Mexican border and seeks to end birthright citizenship in the United States. The following night on Fox News' The O'Reilly Factor, Trump defended his extreme immigration proposals by repeatedly referring to children born in the United States to undocumented immigrants as “anchor babies” and insisting that they are not U.S. citizens. Conservative media have since applauded the presidential candidate for using the derogatory term as other candidates such as Jeb Bush and Bobby Jindal also embraced it.

But, as The Washington Post explained in an August 20 article, “the anchor baby, while potent politically, is largely a mythical idea.” Writing that the term has “little legal underpinning” as “being the parent of a U.S. citizen child almost never forms the core of a successful defense in immigration court,” the articles notes that most children born in the U.S. to undocumented parents “must wait until their 21^st birthday to begin the lengthy process” of helping their parents become citizens:

But usually the debate has been about the residency of the parents, who after all are supposed to be using the child as their “anchor.”

This is the definition that has little legal underpinning. For illegal immigrant parents, being the parent of a U.S. citizen child almost never forms the core of a successful defense in an immigration court. In short, if the undocumented parent of a U.S.-born child is caught in the United States, he or she legally faces the very same risk of deportation as any other immigrant.

The only thing that a so-called anchor baby can do to assist either of their undocumented parents involves such a long game that it's not a practical immigration strategy, said Greg Chen, an immigration law expert and director of The American Immigration Lawyers Association, a trade group that also advocates for immigrant-friendly reforms. That long game is this: If and when a U.S. citizen reaches the age of 21, he or she can then apply for a parent to obtain a visa and green card and eventually enter the United States legally.

[...]

If a person has lived in the United States unlawfully for a period of more than 180 days but less than one year, there is an automatic three-year bar on that person ever reentering the United States -- and that's before any wait time for a visa. So that's a minimum of 21 years for the child to mature, plus the three-year wait.

And, for the vast majority of these parents, a longer wait also applies. If a person has lived in the United States illegally for a year or more, there is a 10-year ban on that person reentering the United States. So, in that case, there would be the 21-year wait for the child to mature to adulthood, plus the 10-year wait.

All told, the parents of the so-called anchor baby face a 24-to-31-year wait to even enter the United States, much less obtain a visa and green card or become a citizen.