President Donald Trump raged at what he called "one of the great scams of our time" in a new Truth Social post on Tuesday. Trump took aim at birthright citizenship in his post, which comes as the Supreme Court prepares to hear oral arguments on Wednesday in a case that could determine whether U.S. citizens will face hurdles to obtaining citizenship for newborns. The birthright citizenship precedent is more than a century old, and some legal experts have said the Trump administration faces a tall task in overturning it. "Birthright Citizenship has to do with the babies of slaves, not Chinese Billionaires who have 56 kids, all of whom 'become' American Citizens," Trump's post reads in part. "One of the many Great Scams of our time!"Trump signed an executive order last year saying children born to parents who are in the U.S. illegally are not eligible for birthright citizenship. The order was swiftly challenged in court.