I don’t think there is any way Congress will approve wording that would justify a strike for being in noncompliance of a chemical weapons agreement. The rebels are also going to soon be crushed with Russia arming the country to the hilt so there won’t be any doubt with another attack who was responsible.
Ultimately ...we will see. http://thehill.com/homenews/senate/321531-congress-slams-brakes-on-all-syria-legislation
There is lots of time now to word it just right and get consensus.