Update 2 - Obama Administration Gains Votes To Secure Iran Deal

Democratic Sen. Barbara Mikulski became the 34th senator to lend her support to the nuclear deal with Iran on Wednesday, giving the Obama administration a hallmark victory.



"No deal is perfect, especially one negotiated with the Iranian regime. I have concluded that this Joint Comprehensive Plan of Action is the best option available to block Iran from having a nuclear bomb," Mikulski said in a statement. "This vote has monumental and enduring consequences."



Her support gives the administration the 34 votes it needs in the Senate to ensure it can maintain a presidential veto of an expected congressional resolution of disapproval.



Congressional Republicans backed by the Israeli government had vowed to do all they can to undermine the deal. They maintained that the deal does not sufficiently block Tehran from building a nuclear weapon, and may lead to a nuclear arms race in the region.



Speaking in Philadelphia, Secretary of State John Kerry responded to the deal's critics saying that sanctions alone were not preventing Iran from making nuclear progress, and that going back on this deal would be a severe blow to Washington.



"Rejecting this agreement would not be sending the signal of resolve to Iran. It would be broadcasting a message so puzzling, most people across the globe would find it impossible to comprehend," he said at the National Constitution Center. "It is hard to conceive of a quicker or more self-destructive blow to our nation's credibility and leadership, not only with respect to this one issue, but, I'm telling you, across the board - economically, politically, militarily, and even morally - we would pay an immeasurable price for this unilateral reversal." 



Israeli Prime Minister Benjamin Netanyahu has been one of the accord's sharpest critics, calling it a "historic mistake", shortly after it was concluded July 14.



"The desire to sign an agreement was stronger than everything else," he said.



Responding to the prime minister's criticism, Kerry said he "respectfully disagrees" with Netanyahu, and that "every threat to Israel and to our friends in the region" would be made worse if Iran were permitted to attain a nuclear weapon.



In a three-page letter sent to all members of Congress, America's top diplomat assured lawmakers that Obama views Israel's security as "sacrosanct", emphasizing that U.S. assistance to Tel Aviv "ensures that Israel can better meet its security challenges".



Only two Senate Democrats have come out in opposition to the deal -- Chuck Schumer of New York, and his New Jersey colleague, Robert Menendez.



But even as the two senators broke party ranks, successive Democratic announcements of support have come in while Congress has been on summer recess - Mikulski's the latest among them. 



While lawmakers could have moved to block President Barack Obama from lifting some of Washington's sanctions on Iran, it could not fully upend the agreement that the P5+1 group of world powers -- the United States, UK, France, Russia, China plus Germany -- inked with Iran.



Still, if they were able to prevent Obama from fully lifting the sanctions that the administration credits with getting Iran to the bargaining table in the first place, it's unclear how Tehran would have responded.



Lawmakers are expected to vote on the agreement by Sept. 17. - Washington DC