China has emerged as a focal point in the debate over US birthright citizenship, as the nation’s Supreme Court appeared sceptical of oral arguments on Wednesday in a landmark case driven by President Donald Trump’s push to restrict the practice.Birthright citizenship “has spawned a sprawling industry of birth tourism,” said Solicitor General D. John Sauer, Trump’s top litigator, in his opening remarks before the highest court in the country.“Uncounted thousands of foreigners from potentially...