H1-B visas/ immigration restrictions are there precisely for that: to prevent the loss of jobs that can be easily learnt/trained. Remember that we are talking of skills that are much more difficult to learn.
Definitely, and in those situation we should welcome them with open arms. I was assuming (perhaps erroneously) that he was speaking towards completely free and open talent-immigration, as in simply hiring an immigrant because they're cheaper and are are completely dependent on you for their visa.
