White House deputy chief of staff Stephen Miller kept up his attacks on birthright citizenship with a far-fetched hypothetical on Friday, and critics lined up to ridicule it.Days after the Supreme Court upheld birthright citizenship in a 6-3 ruling that struck down President Donald Trump's executive order, Miller posted on X that if you believe a foreign government could sail a hospital ship to the edge of US waters, "deliver a hundred babies to foreign moms, then promptly sail back," and that each child "is American for life, you don't believe in nationhood at all." The rant echoed the birth-tourism case he made on Fox News, where he floated a "hard look" at barring pregnant women from the country.Miller's post predictably led to quick backlash. Former Rep. Adam Kinzinger asked sarcastically, "What about our hospital ship that we sent to Greenland? It happened right?" Bulwark journalist Sam Stein quipped, "Well. When you put it that way." Internet personality Damin Toell pointed out that under the 1898 Wong Kim Ark precedent, and still after this week's ruling, babies born aboard foreign government ships in US waters are already exempt from birthright citizenship.Others flipped Miller's logic back on him.National security journalist Marcy Wheeler called his "perverted little fantasy" no more real "than it was for the century and a half since birthright citizenship was codified." Academic Alonso Gurmendi argued that "any citizenship rule can be made to sound absurd like this." And journalist Zaid Jilani went furthest, sarcastically asking: "What if a mom catapults over the US Mexico border and from 500 feet in the air pops a baby out, ties a parachute to it and lets it fall gently to the ground. Does that baby deserve citizenship, lib?"The administration has vowed to keep fighting, though some analysts say the ruling nearly went the other way. Independent estimates put actual birth tourism at a tiny fraction of U.S. births.