The Trump administration announced last Friday that US visa holders who want a green card must first return to their home countries and apply from there, “except in extraordinary circumstances.” On its face, this rule — which was officially promulgated in a memo from US Citizenship and Immigration Services (USCIS) — would upend America’s immigration system and the lives of hundreds of thousands of US residents . Key takeaways The Trump administration’s changes to the green card process could force hundreds of thousands of skilled immigrants to leave the country. This policy represents the triumph of MAGA nativists over the tech right, in the battle to define what an “America First” immigration policy looks like. Precisely how USCIS will implement the policy remains unclear. For more than 50 years , through the “ adjustment of status ” process, visa holders in the United States have been able to remain in the country while applying for permanent residency. This was no small thing.…