The Iran deal must be shit-canned, there is no other alternative. The only reason the left is insuch an uproar over it, is because of their virulent hatred for Donald Trump - It has nothing to do with Iran.
The left wants President Trump to fail, at any cost. Ask yourself this question: How would it look for President Trump to engage North Korea in a de-nuclearization of the Korean Peninsula while at the same time, allowing Iran to further pursue their nuclear ambitions?
You don't achieve greatness in this world by sending mixed signals to your adversaries, and it's pretty obvious that Donald Trump understands that very well.