Where in the constitution does it say he can deny soldiers’ rights to defend themsleves?
It doesn't but that is not the point. All powers to wage war rest solely with the Executive Branch, i.e. The President. Congress controls the money not the war. Passage of this bill would have been at best pointless. In the worst case it would have weakened Presidential powers and given Congress the ability to make military policy...you want Harry Reid deciding ROE?