The news that 34 members of the US Senate are now on record as supporting the Iran nuclear agreement means opponents of the agreement, despite pouring tens of millions of dollars into their campaign, will not have sufficient votes to block the agreement in Congress.Truly, this is a important milestone. Above all, it is a victory for President Obama’s approach of building a broad international coalition and then using diplomacy backed by tough sanctions to tackle this difficult issue.On the other side, those like former Vice President Dick Cheney, who still advance the dangerous and foolish proposition that we should always try first to solve our problems in the Middle East through the use of raw power and military force, have been rebuffed.When this battle began, it seemed as if President Obama and his political allies faced long odds of success. Against him were the entire Republican Party with its built-in majorities in both houses of Congress, urged on by every single one of their presidential candidates.Prime Minister Netanyahu and other Israeli spokespeople spoke incessantly about what a terrible agreement it was, invoking the Holocaust and the 1938 Munich Agreement. AIPAC put $40 million into defeating the agreement – vastly outspending its supporters .Since almost every Republicans in Congress was against the deal – as they have been against virtually everything President Obama has tried to do since the day he took office – the aim of the campaign from the point of view of opponents was to persuade Democrats to oppose it.Had opponents of the agreement succeeded in winning over just 15 of the 48 Democrats in the Senate and 35 of the 188 in the House of Representatives, they would have been able to override a presidential veto. So far, they have received support from exactly two senators and 14 House Democrats. Almost every lawmaker who began this debate undecided and was willing to listen to both sides has ended up supporting the deal.Why? First, because the President and his backers, bolstered by the opinions of most independent experts on nuclear proliferation and monitoring, concluded that this was an excellent deal that did exactly what it was supposed to do, namely prevent Iran from becoming a nuclear power for at least the next generation.Second, because the arguments of the opponents, when boiled down to their essentials, relied more on fear mongering and appeals to emotion than on solid facts.Third, because opponents never put forward a credible alternative. Their contention that there was a better deal out there to be negotiated failed to hold water. Instead, most neutrals were convinced that failure of the deal would immediately lead to a much worse scenario under which Iran would enjoy the benefits of the agreement without having to fulfill its end of the bargain and would be free to move ahead with its nuclear program free of international supervision.Fourth, because opponents of the deal, including the government of Israel, allowed it to become politicized. This was never a bipartisan debate. Opposing the deal became a Republican crusade and Democrats responded to the challenge.Fifth because Democrats no longer fear the political consequences of voting their consciences even when that means going against the Israeli government and the traditional American-Jewish establishment. They realize that these old-guard organizations no longer speak for a considerable segment of the American Jewish community, perhaps even the majority, and that other, more dynamic organizations have sprung up to fill the void.This was an important battle. We will be absorbing the lessons and living with the consequences for some time to come. But those of us who seek diplomatic solutions to tough problems even in the Middle East – and above all to the Israeli-Palestinian conflict – should be encouraged. We have much work to do – but we’re ready to roll up our sleeves again and get back to the task at hand.