President Donald Trump demanded that the Supreme Court reverse its own birthright citizenship ruling, something the justices have done exactly once in their 236-year history.In Trump v. Barbara, the justices voted 6-3 to uphold the 14th Amendment's guarantee of automatic citizenship for virtually every child born on U.S. soil.A rehearing would require the same justices to reconsider a case they've already decided and take a new vote."Citizenship, then and now, was the right to have rights — to freely participate in our political community," Chief Justice John Roberts wrote for the majority. The ruling upheld birthright citizenship for children of immigrants here illegally or on temporary visas."Signs and Billboards are being put up all over our Southern Border, and Mexico, advertising BIRTHRIGHT CITIZENSHIP, with 'Deliveries starting at $4000,'" Trump ranted Wednesday on Truth Social. "AMERICAN CITIZENSHIP IS NOT FOR SALE! In fact, that is a crime, and therefore, the Supreme Court's ruling is wrong.""I will be asking for a Rehearing by the United States Supreme Court, IMMEDIATELY. This miscarriage of justice will destroy America if they don't change their absolutely insane decision."Georgetown law professor Steve Vladeck has called getting the Supreme Court to reverse itself on rehearing "a virtual dead-letter."The Court hasn't agreed to rehear a decided case since 1965. And it has only reversed itself once after rehearing a case — in 1957.For a rehearing to move forward, one of the six justices who voted against Trump would have to push for it. None of the six has. "I am not sure that today's opinion will stand the test of time," Justice Clarence Thomas argued in his 91-page dissent. But the justice has never called for a rehearing.Trump has until July 25 — just 17 days — to formally file his rehearing request with the Court.