> we should encourage immigration through our higher-education system (and we have been doing so for decades)

Having gone through the numbers just yesterday, I was very surprised. So, here's the correction for you. No, america does not encourage immigration through education and subsequent employment. Out of roughly 550k green cards per year, only around 15k are for educated immigrants coming through employment categories (eb1,2,3).

For comparison, there are around 50k diversity visas given in lotteries, and 8k investors visas given out to anyone willing to buy a green card.