[some_guy_there]

The authority asserted by President Trump in the executive order does not arise from the TTPA. It derives from INA (viz. 212(f) of the INA, 8 U.S.C. 1182(f) ). The fact that this order uses the country listed in TTPA does not negate the fact that the executive has asserted the authority to negate already existing visa from any country that they wish to. (Well technically they still have the visa, but what use is it if there is a blanket ban.)

In particular, nothing in TTPA barred entry to people who have helped American armed forces, or legally enrolled students from those country, which this order does. Again, not by authority of TTPA, but under INA. Taking the executive order at face value, the executive can ban any and all countries. The fact that they used the list from TTPA is political convenience.