Bush's report was submitted in the months between the German surrender and the dropping of the atomic bombs on Japan. It was a remarkable context for scientific optimism, given the huge impact of science and technology on the war effort. Radar developments are obviously an unalloyed good for shooting down German bombers.
Scientific progress is arguably even more relevant today, but the vision of the future has changed for the average American. Many achievements of the ensuing eight decades (vaccines eliminating polio and measles, nuclear energy, computing and social networks, cheap solar and wind, fracking, automation and artificial intelligence, cheap spaceflight) are viewed with fear and suspicion by large, different fractions of the US. Unfortunately, ceding scientific leadership to other powers does not reduce the destabilizing force of progress -- but I think there's some explanatory power here in simultaneously shutting down science and pursuing economic isolationism.
While not fully economic isolationism, there was a drive to turn the national focus away from looking outward to gazing at the national navel. Apollo, and much of NASA's ambitious projects, were cut short thanks to defunding in order to deploy those funds towards social projects such as the War on Poverty. The Malthusian worldview of those like Paul Ehrlich led to a system less interested in risk management and more interested in employing the precautionary principle. This often resulted in decisions that were more concerned about the negative aspects of the short term rather than the necessary transitions required to achieve long term goals.
Scientific progress is arguably even more relevant today, but the vision of the future has changed for the average American. Many achievements of the ensuing eight decades (vaccines eliminating polio and measles, nuclear energy, computing and social networks, cheap solar and wind, fracking, automation and artificial intelligence, cheap spaceflight) are viewed with fear and suspicion by large, different fractions of the US. Unfortunately, ceding scientific leadership to other powers does not reduce the destabilizing force of progress -- but I think there's some explanatory power here in simultaneously shutting down science and pursuing economic isolationism.