Updated 1:15 p.m. | Richard J. Durbin saw an opportunity and seized it.

With President Barack Obama’s signature foreign policy achievement and America’s standing with its allies both on the line, and with a void among Senate Democratic leadership, someone needed to step up to ensure the Iran nuclear agreement survived largely Republican opposition.

And the Illinois Democrat was happy to oblige. He’s managed the Democratic floor time. He held a news conference with the administration’s top negotiators, Secretary of State John Kerry and Secretary of Energy Ernest J. Moniz on Wednesday. Throughout August, he repeatedly checked in with members, fielded questions, and managed a whip operation that transformed rampant uncertainty into enough support to, at best, kill the resolution of disapproval in the Senate, and, at worst, uphold a presidential veto.

Talking to senators, staffers and observers, all agree that the effort is consistent with Durbin’s character. But while many see the last month as a reminder of why the veteran lawmaker was chosen for leadership in the first place, it’s unclear what the work portends for his future as Democratic whip — a position he’s held since 2005 — when the presumed Democratic leader in waiting, Sen. Charles E. Schumer, D-N.Y., takes the reins of the caucus next Congress.

Schumer, who did not support the Iran deal, has not publicly backed Durbin despite Durbin’s backing of Schumer as leader. And Schumer’s rumored, preferred candidate, Sen. Patty Murray, D-Wash., has yet to rule out running for the position — with the silence fueling the rumors (though nearly all Democrats have and will argue it’s the media fueling the rumors). A person close to Schumer told CQ Roll Call that: “Schumer is not weighing in on the whip position, and hasn’t expressed a preferred can‎didate.”

What’s more, no senators have publicly said they’ll support Durbin (nor Murray for that matter) for whip next Congress, preferring to keep their thoughts private or arguing that it’s way too soon, 16 months out, to talk about it.

Durbin has regularly maintained he’s secured commitments from enough senators privately to keep the position. But whether intentionally or not, he has done his best to remind senators why they voted for him in the first place.

He wouldn’t comment on the race when asked on Wednesday, saying “my responsibility is minority whip at this point.” But he told the AP in late August: “So for those colleagues who want to know if I’m still up to being whip, I think I’m indicating to them that I enjoy the job, I hope to continue in this capacity, and I hope they’ll support me when the time comes.”

As Congress headed into recess, Durbin found himself in a somewhat uncommon position. Obama strongly supported the deal, but Senate Democratic leadership was undecided and would eventually split positions.

Schumer came out opposed. Both Murray (who is known more for her budget expertise) and Democratic Leader Harry Reid, D-Nev., took some time to support the deal. And the Democrat who would usually take a functional leadership role, Foreign Relations Committee ranking member Benjamin L. Cardin of Maryland, also opposed the deal.

That left Durbin.

“When I got engaged in it, there were no other members of the leadership who had expressed their position,” he said. “So I started working in the caucus, and I worked all through the month of August.”

Durbin claimed business as usual (“That’s what I do, that’s what a whip is.”), adding that he was pleased with the outcome — 42 Democratic senators in support of the deal. He was modest on the future, but in the short term, his efforts have won him a lot of praise from colleagues.

“Dick Durbin showed again, as part of this deal, that when he says something you can count on it,” said Sen. Jeanne Shaheen, D-N.H., who was an early supporter of the deal. “He makes a strong case, he knows his facts, and he’s there and he clearly worked hard on this.”

Sen. Richard Blumenthal, D-Conn., one of the last senators to announce a position, said Durbin didn’t take a hard-line approach to whipping, rather just routine check-ins.

“He in no way exerted pressure, he called to learn my thinking every so often, without trying to persuade me,” Blumenthal said, noting that this vote likely will have little effect on Durbin’s standing in the caucus. “It was high before, it’s high now.”

Sen. Chris Coons, D-Del., who also agonized over the decision for a while, also noted Durbin’s soft-handed approach.

“Senator Durbin as the whip played an appropriate role within the caucus to check in, keep a sense of where people’s thinking was, but he did not particularly, as it were, whip the vote, in my case,” Coons said, noting that many of his colleagues in addition to Durbin offered help and support.

Sen. Tim Kaine, D-Va., also praised Durbin’s efforts.

“That’s a hard thing to do,” Kaine said. “It hasn’t really been a whip operation in the traditional sense because this is a big tough issue and people are going to have different points of view.”

The Iran deal isn’t Durbin’s first time being bold on foreign policy. In 2002, he was one of only 23 senators, including Murray, to vote against the authorization for use of military force in Iraq — a vote that’s become a Democratic touchstone. (Reid and Schumer supported the AUMF, while Cardin opposed while still in the House.)

Schumer received an avalanche of criticism following news of his opposition to the deal, including protests against his leadership. One outspoken group, MoveOn.org, offered glowing praise of Durbin.

“Not that he needed it, but this was the ultimate job interview for continued leadership,” said Ben Wikler, the Washington director for MoveOn.org. “I think throughout the decades to come, his voice in helping deliver Democratic votes for the Iran deal is going to make America safer and strengthen its position in the world.”

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