'Long road' remains ahead as bill garners 73 co-sponsors one year after its introduction in Congress, advocates say.
Hamawy's victory in New Jersey likely to make him a rare US Congress member with firsthand experience in besieged Gaza.
Democrat Ro Khanna and Republican Thomas Massie say they will try to remove the pro-Israel section from US defence bill.
Eastern state could play a key role in deciding the balance of power in the US Congress in November midterm elections.