The GOP candidates are pledging to undo the Iran nuclear deal. Don't buy it.

If the past is any indication, I don’t expect Republicans to find the time to discuss what would actually happen if they got their wish, since they’ll be too busy throwing Munich analogies around. But let’s assume that the deal doesn’t get shot down in Congress, and it begins to take effect. A year from now, what will the GOP nominee say about the deal? What if it seems to be working — the sanctions have begun to be unwound, inspections are proceeding, and there’s no indication yet that Iran is secretly trying to create nuclear weapons. What then? Will that nominee say, “I don’t care if it looks like it’s working, Bibi Netanyahu once showed me a picture of a cartoon bomb, so I’m still going to walk away from this agreement”?

Maybe. But the truth is that the next president abandoning this agreement has about as much likelihood of happening as Donald Trump’s plan to convince Mexico to pay for a 2000-mile wall between our two countries. It’s the kind of thing a candidate says when he wants to sound tough, but it’s not the kind of thing a president — even if it’s one of these guys — actually does. It would get us virtually nothing, and potentially cost us a great deal.

Think about that when you see the candidates shouting at the cameras after Congress fails to stop the agreement, pledging to do their utmost to destroy it.