The ACA proposal accepts CBT (citizenship-based taxation) and recommends getting rid of the Foreign Earned Income Exclusion which is a benefit to many Americans abroad. The proposal does leave the FTC credits intact which will (for certain people) mitigate double taxation a bit.
Americans abroad will almost always be subject to higher U.S. taxes than a comparably situated homelander. See:
U.S. Persons Abroad - Members of a Unique Tax, Form and Penalty Club 
So does this mean Americans will be taxed double…for working AND living abroad???
The ACA proposal accepts CBT (citizenship-based taxation) and recommends getting rid of the Foreign Earned Income Exclusion which is a benefit to many Americans abroad. The proposal does leave the FTC credits intact which will (for certain people) mitigate double taxation a bit.
Americans abroad will almost always be subject to higher U.S. taxes than a comparably situated homelander. See:
http://isaacbrocksociety.ca/2017/02/17/poll-is-it-common-for-americansabroad-to-have-a-higher-u-s-income-tax-bill-than-a-comparably-situated-homelander/
and the comments.