Supporters of the Iran nuclear deal see growing momentum on their side in the Senate, raising the possibility they'll be able to block a disapproval resolution and protect President Obama from having to use his veto pen.
Such an outcome – which looked all but inconceivable in the days after the deal was signed July 14 – remains a long shot. It would be a major victory for Obama, who is staking his foreign policy legacy largely on the agreement struck by the U.S., Iran, and five world powers to dismantle most of Iran's nuclear program in exchange for billions in sanctions relief.
It would take 41 senators to block the disapproval resolution scheduled for a vote next month; only 34 lawmakers would be required to uphold an Obama veto of such a resolution.
Sen. Patty Murray (D) of Washington on Tuesday, became No. 29 on the list of Democrats and independents who have publicly announced their support of the deal.
"This is not a perfect deal, and there are several elements I would like to be stronger," Murray said. "But after working my way through the details and the alternatives, losing a lot of sleep, and having a lot of good conversations with so many people, I am convinced that moving forward with this deal is the best chance we have at a strong diplomatic solution. It puts us in a stronger position no matter what Iran chooses to do, and it keeps all of our options on the table if Iran doesn't hold up their end of the bargain."
Two Senate Democrats – New York's Chuck Schumer and New Jersey's Bob Menendez – have announced that they will vote against the agreement. But supporters feel confident that they can get to 34 votes, and some have begun to say in private that 41 votes may even be within reach.
Many caution it remains a remote possibility with Republicans unanimously opposed and Israeli officials arguing vehemently against a deal they say could empower enemies sworn to their destruction. And yet predictions that Republican opponents and the powerful-pro-Israel lobby would use Congress' August recess to make the deal politically toxic have not come to pass.
Although polls register significant public concerns about the agreement, undeclared Democratic senators have increasingly broken in favor. In addition to Murray, who's a member of the Senate's Democratic leadership, Minority Leader Harry Reid of Nevada announced his support over the weekend, and Sen. Debbie Stabenow of Michigan followed on Monday.
"We feel good about the fact that after two-thirds of the Democratic caucus has committed that we have substantial support for the president with only two dissenters," Sen. Dick Durbin (D) of Illinois who's leading the whip operation in favor of the deal, said in an interview. But Durbin declined to predict success, saying, "We continue to work it."
Reid told reporters in Las Vegas attending a clean energy conference Monday that he expects to see a couple more "yes" votes in the next couple of days.
"I know it's a long shot, I hope that it can be done," he said of prospects for blocking the disapproval resolution. "We'll just have to see. Because right now, it's based on a whole lot of uncounted votes."
The possibility that Democrats could filibuster the disapproval resolution angered some of the deal's opponents.
"Harry Reid wants to deny the American people a voice entirely by blocking an up-or-down vote on this terrible deal," Sen. Tom Cotton (R) of Arkansas said in a statement. "He is obstructing because he is scared."
Several key Democratic senators have yet to announce their position. One of the most-watched is Sen. Ben Cardin of Maryland, who is the top Democrat on the Foreign Relations Committee and whose position could influence colleagues.
Congressional aides say they've rarely seen the White House work an issue so hard, with Obama making personal appeals to undecided lawmakers.
"We've been leaders in nonproliferation, which is part of the reason why I am so insistent that Congress not block a historic diplomatic effort when it comes to making sure that Iran does not get a nuclear weapon," the president said at a fundraiser Monday night in Henderson, Nev.
The disapproval resolution is certain to pass the House, though Democratic leader Nancy Pelosi has declared that Democrats have the votes to sustain an Obama veto. Two-thirds votes are required in each chamber to override a presidential veto.