You trust a guy who spent his last campaign telling conservatives that an earned path to citizenship for illegals is de facto amnesty before backing an earned path to citizenship for illegals as a senator, don’t you?
He’s not telling you the truth here. Or rather, he’s grossly simplifying the choice he’ll have as president on what to do about Obama’s Iran deal. If there’s evidence circa January 2017 that Iran is cheating by enriching uranium covertly beyond what the executive agreement with O provides, then yeah, there’s a chance that President Rubio will seize that as a reason to tear the whole thing up. But if there’s no evidence, or if the evidence is weak enough that America’s European partners aren’t inclined to abandon the deal just yet (which is likely), Rubio’s not going to begin his presidency by pissing them off and rescinding the agreement they negotiated with the current White House. Obama’s approach to a nuclear bargain with Iran is similar to his approach to executive amnesty in the sense that, while it’s not legally binding on his successor, it’s politically binding. Rubio won’t summarily cancel O’s executive order on immigration, especially if he overperforms with Latino voters next November, and he won’t summarily cancel the Iran deal, especially since he’ll need European cooperation for other elements of his foreign policy, starting with containing Russia. The sooner Obama can lock this deal down, the more time American voters will have to get comfortable with it before his successor takes office, and thus the harder it’ll be for that successor to upset the status quo without a good reason. The strategy behind all of O’s power grabs is to have political reality bind future administrations to his will even when the law says otherwise.
But political reality for a Republican candidate cuts two ways. Rubio won’t tear up Obama’s agreement with Iran without a reason but he’ll have to satisfy the righty hawks who voted for him believing that he’d keep this promise. One way to do that is to punt the matter to Congress and hope that they tear up the deal for him: If he can’t get two-thirds of the Senate to ratify it as a formal treaty in 2017, then he’ll walk away from it and say hey, I tried. Problem is, that won’t help him with the Europeans. They’ll want to know why he’s handing off the deal to Congress instead of sticking with the status quo. So what Rubio could try instead is to expand on the deal somehow by demanding concessions on, say, Iran’s ICBM program too, a point he brings up with Hugh Hewitt here. Our EU allies won’t be crazy about that either but at least that move will have been made in the (ostensible) spirit of the original agreement, making sure that Iran can’t weaponize its nuclear materials. If Iran says no then Rubio could walk away claiming that not only did he try to preserve the deal, he actually had no choice but to ask for new concessions given how Obama’s plan would allow Iran to ramp up enrichment again after 10 years. The clock is ticking; what was O’s successor supposed to do, just stand by and wait while they develop intercontinental delivery systems? So there’s your outlook. For the next 20 months, Rubio will promise to shred the deal and then, come January 2017, he’ll start promising to add some real teeth to it. The test will be what happens if/when Iran says no.