Hours before Chinese President Xi Jinping arrived in the US for a high-stakes summit, US Secretary of State Marco Rubio moved to restrict visas for those who “engage in or facilitate” birth tourism, a practice the Trump administration has increasingly accused China of.“By restricting visa issuance of those who both engage in and profit from this fraud, we are sending a clear message: the United States will not allow foreigners to exploit our immigration system and violate the sanctity of US...