Long before Donald Trump, birth tourism, and today’s debate over birthright citizenship, there was a son of Chinese immigrants named Wong Kim Ark.

And the story of Wong Kim Ark shows why many legal scholars think Trump probably won’t succeed in his plans, revealed Tuesday, to end the practice of bestowing U.S. citizenship to babies born on U.S. soil. Ark’s fight wound up being the basis of a little-known Supreme Court case that has a outsized effect on the debate over birthright citizenship.