For months, a group of Republican and Democratic senators have been working to craft legislation that would give Congress a means to debate and weigh in on a potential nuclear agreement with Iran. They now have that hard-won bipartisan agreement, and President Obama has grudgingly agreed not to veto it if passed in its current form.

But thanks to two other GOP senators, Marco Rubio of Florida and Tom Cotton of Arkansas, that legislation may yet fail. Among other things, the two insist on an amendment to the bill requiring that Iran recognize Israel's right to exist before a deal can be consummated.

“Who could object that Israel has a right to exist as a Jewish state?" Cotton asks, brimming with all the innocence of a fox with chicken feathers stuck in its teeth.

If Cotton and Rubio get their way -- if they succeed in presenting their amendment on the Senate floor -- a line of dominoes would begin to fall:

1.)  The amendment would pass. As Cotton suggests, "who could object"? A vote against the amendment would be depicted -- falsely -- as a vote against Israel's right to exist, and such is the state of American politics that few senators would be willing to take that risk.

2.) However, Iran isn't going to recognize Israel's right to exist any more than Israel is going to recognize Iran's right to nuclear weapons. One is as non-negotiable as the other. In short, a bill requiring Iranian recognition of Israel is a bill that would doom negotiations, and for that reason Obama and his Democratic allies won't accept it. The bipartisan compromise negotiated in the Senate would blow up, just as Cotton and Rubio intend.

3.) With the bill dead, Congress would have no other mechanism by which to weigh in on a deal with Iran, should one be achieved. Cotton and Rubio know that, and offer no alternative to it. They just don't care. They care only that they want to get their way. Wrapped in the bubble of their own absolute certainty, the consequences of their stance are somebody else's problem.

There is, however, at least a consistency in their stance. They don't like the deal negotiated with Obama and the Democrats because while it might be achievable, it doesn't give them everything they want. They don't like the preliminary deal negotiated with Iran for the same reason. In Congress as on the world stage, they behave the same way.

And if they do succeed in their larger goal of destroying any chance of a negotiated settlement?

Well, they don't care about that either. That too is somebody else's problem. They and other opponents of negotiation have been asked repeatedly for their alternative plan for how to stop Iran's nuclear program. Apparently, their plan is to demand and get Iran's surrender. Their plan is for the mullahs running that country to decide to go commit suicide, and for a new generation of pro-American, pro-Israeli Iranians to appear by magic out of Aladdin's lamp and take control of that country. They seem certain that such a thing would happen -- certainty being their defining trait -- even though they cannot provide a plausible scenario by which it might.

The sophistication and maturity of their political judgment is also reflected in the Twitter war that Cotton began this week with Iran's foreign minister, in which the American senator personally insulted the Iranian diplomat, attacking him as a coward. As in their earlier exchange, the Iranian foreign minister ended up showing much more class and dignity than did Cotton. All Cotton achieved was the further embarrassment of himself and unfortunately of his country.

But Rubio is the more troubling case. This is undoubtedly part of his strategy to portray himself as Obama's chief antagonist on foreign policy, and you do have to expect a certain degree of such posturing with an election coming. But again, he shows no sign of having thought this through. He is proving himself capable of destroying solutions crafted through the hard work of others, but no capacity for creating such solutions himself.

The sad part is, that makes him the perfect standard bearer of the modern Republican Party.