He is talking about attracting and keeping the individuals of exceptional talent and value here. That's how USA beat Germans and Russians in creating first nuclear weapon, then later Russians in the space race.
Solid state physics of semiconductors and computer architecture developed in 1940s-50s by the same generation of European refugee scientists and engineers (von Neumann, Behe, Wigner, etc; mostly from Hungary, Poland and Germany) was the basis for computer revolution that followed from 1970s. Or electric power and radio technological revolutions which started from the beginning of 20th century were creations of another refugee, Nicola Tesla from Balkans.
It's good for all of us if the best and the brightest from the whole world end up here.
The creativity of each such individual ends up generating far more jobs than that one position such person would "steal" from one American (who may not exist in the first place). Keeping them away is penny wise and pound foolish.
H-1B is wage lowering scheme.
Nice fantasy.
Here’s reality:
We aren’t bringing in the “best and brightest.”