Up next: Keep fighting, or demand enforcement

When she became the 34th U.S. senator to publicly support the Iran nuclear deal, thereby stripping Congress of its power to block the Obama administration-brokered accord, Sen. Barbara Mikulski (D-Md.) altered the political calculus for the deal’s opponents.

Now, those who have strongly campaigned against the 159-page agreement face a choice: continue their vociferous opposition, or call for the strictest possible implementation of the deal.

“For those who oppose the deal, killing it would obviously have been the preferential outcome,” Larry Hanauer, a senior policy analyst for the RAND Corporation think tank, told JNS.org. “Having failed to do so, comprehensive implementation of the deal is going to be the biggest constraint on Iran’s nuclear program.”

Following Mikulski’s support, Sens. Cory Booker (D-N.J.), Mark Warner (D-Va.), and Heidi Heitkamp (D-N.D.) also backed the Iran deal, while Sen. Ben Cardin (D-Md.) opposed it. Though President Barack Obama surpassed the 34 affirmative votes needed to sustain his veto of any Congressional rejection of the agreement, the White House needs three more votes to block a vote against the pact.

Without 41 pro-deal votes, Obama would need to use his veto. At the same time, some deal opponents would see 60 anti-deal Senate votes as an important policy statement, despite Obama’s inevitable veto.

“Today, we know that the Senate will not override a presidential veto of legislation that will disapprove the nuclear deal with Iran,” wrote Robert A. Cohen, president of the American Israel Public Affairs Committee (AIPAC), in a mass email the day Mikulski announced her vote.

“However, we also know now that once the votes are tallied, a bipartisan majority of America’s representatives in Congress will oppose this deal…. Now, days before the Congressional vote, I’m writing to ask you to keep fighting for a better deal,

Congress has until Sept. 17 to weigh in on the deal before its 60-day review period expires. 

“Many members of Congress are still undecided,” Cohen wrote. “We must continue to engage them and make our case.”