[ancient_geezer]

This article itself, and the threat to leave the US, is itself no more than another method of landing a blow.

Ahmmm! it isn't just the threat, when it is actually happening. The issue is not whether it could happen, but rather how to reverse the trend.

[americanbychoice2]

For 16 years I lived in Europe and was considered an expatriot. I am now retired and live in the US again. I don't even consider moving back, even though I have an aging and ill mother in Germany. I simply could not afford living there anymore.
One very big and obvious fact was omitted though. The US is the only country that taxes an American citizens global income regardless of residency. I had to file a 1040 every year. There is such a thing called an international double taxation treaty which makes you pay the greater of the taxes. For instance, if an American pays no taxes to the host country, he/she will pay taxes to the US government without reaping any of the benefits.
Therefore, a "top 1% earner" will pay almost the same taxes to the US if he/she left or stayed in this country.