VIENNA -- Tuesday's announcement of an historic nuclear deal between world powers and Iran has been met with emotional responses in Washington that do not fall cleanly down party lines.Senators, congressmen and Jewish American organizations issued statements as news broke ranging from tepid endorsement to hostile rejection, with near unanimity against the deal emanating from the Republican Party. Opponents of the deal went beyond Washington's typical politics and rhetoric, and expressed their fears with a gravity that seemed to match the objective significance of the moment. And the historic nature of the Comprehensive Joint Plan of Action, of its implementation and of its consequences on the Middle East was immediately clear to everyone with a vote or vested interest in its outcome.J Street, an organization primarily concerned with the conflict between Israel and the Palestinians, applauded the agreement. But the American Israel Public Affairs Committee, the American Jewish Committee, B'nai B'rith International, the Anti-Defamation League and the Jewish Federations of North America all expressed profound concerns on their initial reading of the JCPOA, and all called on Congress to conduct a thorough congressional review.Required by law to submit the nuclear agreement to Congress within five days of its adoption, the Obama administration began mobilizing immediately an aggressive effort to maintain Democratic support. Congress is allowed, but not required, to hold a vote of approval or disapproval of the deal within sixty days of its receipt.It is sure to take the opportunity. Senate Majority Mitch McConnell (R-Kentucky) said that Congress understood the seriousness of their charge to review the 159-page document, but said the administration had a "tough sell" to hold on to 34 Democrats. That will be required of the White House in order to sustain a veto should Congress vote to disapprove of the deal.Preparing for the fight ahead, US President Barack Obama began his effort with a media blitz: A formal statement from the State Floor of the White House, interview opportunities with several National Security Council principals, a sit-down with New York Times commentator Tom Friedman and a press conference with correspondents on Wednesday morning all dominated US media headlines with the administration's argument."I think that this builds on bipartisan ideas, bipartisan efforts," Obama told Friedman. He vowed to veto any resolution of disapproval, and called such a vote "irresponsible" and "misguided.""You test these things, and as long as we are preserving our security capacity— as long as we are not giving away our ability to respond forcefully, militarily, where necessary to protect our friends and our allies— that is a risk we have to take," he said.Obama insists that this deal— which seeks to cap, restrict, monitor and partially roll back Iran's nuclear program for a finite period— is exclusively about Iran's nuclear program and does not represent a rapprochement between Washington and Tehran.But "there are better or worse approaches that Iran can take relative to our interests and the interests of our allies, and we should see where we can encourage that better approach," he said, adding: "Even with your enemies, even with your adversaries, I do think that you have to have the capacity to put yourself occasionally in their shoes."Iran will have access to $100-150 billion in frozen assets abroad within short order under the agreement. The administration argues the money is likely to be used on infrastructure and other domestic projects inside Iran, but Arab powers and Israel fear it will be used to fund Tehran's proxy militias across the region."We've got an historic chance to pursue a safer and more secure world," Obama said at his press availability. "I'm determined to seize that opportunity."The president was asked several times to directly address Israel's concerns, expressed loudly and without varnish once the deal was announced in Austria's capital on Tuesday morning. After campaigning against adoption of the deal in its current form for over a year, Prime Minister Benjamin Netanyahu called the agreement an "historic" mistake with catastrophic consequences for Israel and its neighbors across the wider Middle East."It's a national US security interest to see to it Iran doesn't send weapons to Hezbollah," Obama asserted, condemning Tehran's funding of the group and noting that Israel has " legitimate concerns about its security relative to Iran."But he repeatedly stated that Netanyahu had yet to provide a reasonable alternative, and said that his criticism— and those of his US ambassador, Ron Dermer— "defies logic, it makes no sense, and it loses sight of our original number one priority" of preventing Iran from building the bomb.Opponents have a messaging strategy, too. AIPAC is preparing a rare and transparent push to lobby Democrats against their own president entering an election year. A vote for the deal, they will argue, is a vote categorically against Israel and for a less stable Middle East."We strongly believe that the alternative to this bad deal is a better deal," AIPAC said in a statement. "Congress should reject this agreement, and urge the administration to work with our allies to maintain economic pressure on Iran while offering to negotiate a better deal that will truly close off all Iranian paths to a nuclear weapon."AJC's executive director, David Harris, said in a statement that the "immensely high-stakes nature" of the deal placed a tall order on Congress to review it with strict scrutiny."That process should be driven by one central question," Harris asked: "Will the deal enhance the security of the United States, our allies in the Middle East, and the world? If so, then it should be supported.""If not," he continued, "then it must be opposed."And while initially quiet, the Orthodox Union said on Wednesday it had reviewed the agreement in its entirety, found it "seriously wanting," and now plans on mobilizing rabbis and synagogues across the country to oppose it once it reaches Capitol Hill.Taken collectively, the efforts of these groups will be a powerful display of political action from the American Jewish community— one rarely exerted against a sitting president. But most aides on the Hill believe the argument against a deal will be a tough sell, regardless of the weaknesses of its details.That is, in part, because of the built-in soap box the White House has at its disposal, and the difficult politics of failure Democrats would face if an international agreement were undermined at home.But Obama's aides and their surrogates will argue that a vote against the JCPOA is a vote for war, against peace, without any realistic alternative and, ultimately, a move that would undermine the president himself.US Secretary of State John Kerry went even further on Tuesday, stating that the US would be in "noncompliance" of its own agreement, and would be "turning its back" on the international community, which the president says is currently unified behind the deal.One key Democrat, Hillary Rodham Clinton, is walking a very thin line. Her statement in support of the agreement was cast in between several caveats, and acknowledged that, if elected president in 2016, she would be the one tasked with enforcing it."Based on the briefings I received and a review of the documents, I support the agreement," Clinton said in an e-mail to reporters, explaining, "it can help us prevent Iran from obtaining a nuclear weapon."She did not explicitly say the deal will, verifiably, prevent Iran from obtaining that weapon, as the Obama administration and its international partners assert.The former secretary of state made note of her own personal role in "twisting arms" to put in place a global sanctions regime against Tehran which, she says, brought them to the table in the first place. And she expressed sympathy with critics of the deal."I know that there are people of good faith who opposes this deal— people I respect," she said. "They raise concerns that have to be taken seriously. They are right to call for extreme vigilance."Indeed, on this point, Obama agreed: "People's concerns here are legitimate," he told Friedman. "They're not just being paranoid."