[...] Its supporters, including the Obama administration, have touted the H-1B as a way to inject highly sought-after skills into the US talent pool. But more often, critics say, big companies exploit it to reduce labor costs, leaving more and more skilled American tech workers out of a job. "There are literally tens of thousands of American workers who have trained their foreign replacements," says Ronil Hira, a public policy professor at Howard University and a leading authority on H-1Bs. "And the workers being imported have no more than ordinary skills that are abundantly available in the US." [...] it...