Clearly there are checks and balances on the power given to the President - and for good reason as we are seeing here.   Your scenario is convoluted and based on zero empirical evidence.  On the other hand, Trump plainly stated his intention to ban Muslims and instructed his staff to find a "legal" way to do that.  Why do his words mean nothing to you?  Trump plainly stated his intention to target Muslims.  His Republican supporters are celebrating this targeting.  

It is not more complicated than that.