Washington (CNN)Chuck Schumer's fate as the next Senate Democratic leader is getting complicated.
Schumer, White House spar on Iran vote
Allies of the Obama administration are pouncing on the New York senator's decision to oppose the president's landmark Iran nuclear deal and questioning whether the move should cost him his anticipated leadership promotion in 2017.
Schumer, the highest-ranking Jewish lawmaker on Capitol Hill, has been viewed as the most influential member in deciding whether to approve the agreement in a mid-September vote.
Coming out strongly in opposition -- as he did in a lengthy statement late Thursday -- could sway other Democrats who the White House wants on its side to sustain an anticipated veto, especially those who, like him, have a constituency highly critical of the deal.
Now many of President Barack Obama's associates and progressive groups such as MoveOn are warning that his expected replacement of Senate Minority Leader Harry Reid when the Nevada Democrat retires next year could be in jeopardy.
White House spokesman Josh Earnest said Friday he "wouldn't be surprised" if Senate Democrats take Schumer's decision into account when deciding whether to name him their next leader.
Dan Pfeiffer, a former senior adviser to President Obama and a CNN contributor, said Schumer is on shaky ground.
"If the deal goes down, Schumer will be see as directly responsible," Pfeiffer said. "I think most of the Obama sand Clinton wings of the party will never forgive him."
Despite the backlash, several current and former Senate aides said Schumer has nothing to fear.
"This has no effect. Last time I checked, former Obama aides and/or outside groups don't really have a vote within the Democratic caucus," said Jim Manley, a Democratic strategist who spent six years working for Reid.
And a current Senate Democratic aide did not foresee problems for Schumer when it comes to the leadership post.
"I would say it's more short-term frustration, but I think it will have passed by the time this actually comes up," the aide said.
So far, no senator has publicly called for any change to the current leadership succession plan. A source close to Schumer noted that groups like MoveOn have long-opposed him but did not prevent him from winning the backing of everyone in the caucus when Reid announced his departure.
"His decision on the agreement is not going to surprise any of his colleagues," the aide said.
Schumer is not only opposed to the deal but planning to vote to override Obama's anticipated veto. Both chambers are expected to pass resolutions of disapproval after the current 60-day review period. With the vast majority of Republicans opposing the agreement and the White House is hoping to win enough Democratic support for the deal to help sustain his veto.
The House would vote first on a veto override and the deal's supporters are confident they have the votes to sustain the president's veto there. Only one chamber needs to sustain the veto for the White House to be victorious.
Earnest said the White House was informed ahead of time that Schumer planned to come out against the deal.
Not everyone agrees that Schumer is safe from a leadership challenge, however. A key Democratic aide with knowledge of the leadership process in Congress said Schumer's stance on the deal could jeopardize his rise, depending on how much he pushes his case.
"It depends on whether or not he whips against the deal," the aide said. "I know his statement says he won't, but that seems incredibly hard to believe."
Schumer said Friday that he doesn't expect to sway significant numbers of his colleagues.
"There are some who believe that I can force my colleagues to vote my way," he said. "While I will certainly share my view and try to persuade them that the vote to disapprove is the right one, in my experience with matters of conscience and great consequence like this, each member ultimately comes to their own conclusion."
The Democratic aide, though, said that Schumer was already in dangerous territory.
"The statement itself is a clear attempt at persuasion," he said, referring to Schumer's explanation Thursday of his decision to vote "no" on the deal. "He talks to members constantly. The idea that Iran will never come up and he won't try to persuade folks on some level defies common sense and his own nature."
The aide said Schumer's ascension to leadership post is not set in stone.
"He says he has the votes but something like this could change that," the aide said. "All someone has to do is announce a challenge and all bets are off. This issue runs incredibly deep for Democrats. Echoes of the Iraq war abound."
Earnest noted in his briefing that the ideological dispute between Schumer and Obama goes back to their different votes on Iraq -- Schumer for, Obama against -- and that the New York senator's opposition on Iran was "not particularly surprising to anybody here at the White House."