President Obama’s ambition to get the Iran deal done suffered a blow today. The Senate Foreign Relations Committee unanimously approved the Corker-Menendez bill, as amended by a compromise between Sen. Corker and new ranking member Sen. Ben Cardin (D-MD). The new bill was largely a victory for Republicans, skeptics of the bill, and proponents of Congressional oversight. The overarching structure that freezes the President’s ability to suspend sanctions in the wake of a final deal until Congress had time to approve or reject it remains in place, and apparent “concessions” may have actually strengthened the bill. The freeze period was shortened, but restructured in a way that put pressure on the Iranians to sign a deal on time and the Administration not to delay in fully briefing Congress.And while the removal of a requirement that the Administration certify that Iran was no longer engaging in terrorism was disappointing to some Republican members, the amendment probably sharpens the bill. By limiting Corker-Menendez to the nuclear question, the new language focuses the bill as a mechanism to set up a straight yes-no vote on what the Obama Administration ultimately achieves. And in return, if the final deal is OK’d, the Administration will have to provide 90-day reports to Congress that Iran is still complying with the nuclear deal, or sanctions come back. No North Korean sign-and-cheat moves here, the Senators say.There can be no doubt that the unanimous passage was a major setback for the Administration. As it became clear this morning that the Corker-Cardin compromise would have enough votes to override a veto, the White House caved, withdrawing its veto threat. And absent White House opposition, there was no benefit—and a lot of potential political cost—in fighting the bill—hence the unanimous vote.Whatever the timeline may be, it’s clear that Sen. Corker views today’s hearing as far more than a tactical victory on a single issue. Corker has for some time dreamed of resurrecting the SFRC’s historic role in U.S. foreign policy. Today’s vote was a small but significant step in that direction. It was also a personal triumph for Corker, the product of months of canny management of a committee that includes Republicans ranging from Rand Paul to Marco Rubio and Democrats from Bob Menendez to Barbara Boxer. He abstained from the Cotton letter, preserving credit with his Democratic colleagues, and yet held the Administration’s feet to the fire over the core of his bill. For the rest of his time in office, whenever President Obama wants to push the generally-accepted boundaries of U.S. foreign policy (as he clearly seems inclined to do), he’ll have to be aware of where the Senator stands, and consider what Corker might do.As for the bill itself, it will now head to both Houses; it’s likely to pass and be signed. More broadly, ever since the announcement of the Iran nuclear “framework,” doubts epitomized by the analysis of former Secretaries of State Kissinger and Shultz have seeped further and further into the mainstream of U.S thought. The cards are still stacked in the Administration’s favor, but after today it’s legitimate to ask: will the White House be able to hold the line until June?