Imagine there is a war and a draft needed. We can draft the those who were anchor babies to fight for us. If they are living abroad, we can still draft them. They owe that to the republic as citizens! When they don’t show up, we can charge them for draft dodging. If they are caught in the USA, they can be prosecuted and imprisoned and they know it.
(Not gonna happen, of course, but the idea is to prevent mommies from coming here and dropping a kid on US soil.)
There is no extradition for the thousands of Chinese anchor babies.
Britain tried to do that to U.S. citizens (impressment) in the War of 1812.
Because voluntary enlistments could never satisfy the demand for sailors, the British resorted to the use of press gangs to forcibly place men into service. As many as half of all seamen manning the Royal Navy were impressed. About 10,000 Americans found themselves impressed into service during the Napoleonic Wars. The British argued that the sailors it impressed had escaped from their navy. When Americans protested against the seizures, British authorities justified their practice by arguing that being a British subject took precedence over claims of American citizenship.
Welcome to Fantasy Island!
As if the vague prospect of a draft will disincentivize a mother.