The GE corn is specifically engineered to be tolerant of glyphosate. That way you can spray it all over the fields and it kills the nutrient stealing weeds and not the corn. It seems their goal is to get rid of the GE corn and outlawing glyphosate to reduce the demand for the GE corn is a big part of the process.
So, non-glyphosate herbicides aren't really relevant to the goals of the program.
No, my point is that if the problem is cheap imports of ready-to-eat corn is the problem, then only banning glyphosate itself will do nothing to stem that. If it's banned alongside GMO corn imports, that's a different matter.