Of course he supports it! He gets cheap, legal labor that way!
This about sums it up:
"Gates, who runs a foundation with his wife that is the world's largest charity, said flexibility of movement for higher-skilled workers was especially important for his global company.
"I think every country in the world should make it easier for people with high skills to come in," he said.
In a recent address to a U.S. Senate committee, Gates said scientists and engineers from India and China working at his giant software firm routinely waited more than five years to get a U.S. green card."