Weeks before President-elect Donald Trump is to take office, a major rift has emerged among his supporters over immigration and the place of foreign workers in the U.S. labor market. The debate hinges on how much tolerance, if any, the incoming administration should have for skilled immigrants brought into the country on work visas. The schism pits immigration hard-liners against many of the president-elect’s most prominent backers from the technology industry — among them Elon Musk, the world’s richest man, who helped back Trump’s election efforts with more than a quarter-billion dollars, and David Sacks, a venture capitalist picked to be czar for artificial intelligence and cryptocurrency policy. The tech industry has long relied on foreign skilled workers to help run its companies, a labor supply that critics say undercuts wages for American citizens. The dispute, which late Thursday exploded online into acrimony, finger-pointing and accusations of censorship, frames a policy quandary for Trump. The president-elect has in the past expressed a willingness to provide more work visas to skilled workers, but has also promised …