In a system of capitalism there are no gaps or shortages, just disequilibrium between demand and supply that determines price. The current "science gap" is that U.S. produced "science" is price uncompetitive with global "science". Same problem as in automobiles or consumer electronics. Even U.S. Government knows this; e.g. NASA uses Russia whenever possible to "do science" to stretch its $.
U.S. talent is naturally seeking highest value occupations: e.g. financial engineering, law, management, health care etc., As long as these occupations are valued more by market (than "science"), it is absurd to talk of "science gap", especially when global markets are producing enough "science".
A day may come when the currently lucrative occupations may not be so anymore; then the talent may flow to "science" if "science" has more relative market value.
Two years back, mortgage & real estate were highly lucrative; now, many previous 6 figure earners are on food stamps. May happen to financial engineering too some day.