U.S. Sen. Charles E. Schumer (D-N.Y.) said Thursday night he would the oppose the Iran agreement. (Joshua Roberts/Reuters)

The White House aggressively struck back Friday after Sen. Charles E. Schumer announced his opposition to President Obama’s Iran nuclear deal, suggesting the New York Democrat could lose support to become ­party leader in the Senate in 2016 if he helps block the accord.

The response was the latest ­example of the president’s ­take-no-prisoners approach to ensuring the survival of a pact he views as a legacy-defining achievement that could help remake the security situation in the turbulent Middle East.

The White House and its allies expressed confidence that Schumer’s opposition would not be enough to derail the Iran deal. Senate Democratic aides said 15 members of the caucus have expressed support, and Schumer is the only one to publicly oppose it.

But both sides acknowledged that the debate is now headed into a period of uncertainty as Obama leaves town for a two-week vacation in Martha’s Vineyard and Congress breaks for its six-week summer recess. As lawmakers head home to their districts, some are expected to be confronted by constituents who oppose the deal, and several influential Jewish American groups have launched multimillion-dollar advertising campaigns against it.


Although Schumer indicated that he would not actively encourage others to vote against the Iran deal, the White House moved to marginalize his position, citing his support for the Iraq war in 2003 as part of a long-standing tendency to disagree with Obama on foreign policy and the use of American power.

White House press secretary Josh Earnest dismissed Schumer’s stance, saying it is “not particularly surprising to anybody here at the White House, even if it was disappointing.”

Schumer’s position “doesn’t change our confidence that we’ll be able to mobilize a substantial majority of Democrats,” Earnest said, but he suggested lawmakers should question whether Schumer is fit to become the party’s leader in the Senate, saying members may want to “consider the voting record of those who want to lead the caucus.”

Close White House allies made similar arguments.

“Senator Schumer siding with the GOP against Obama, [Hillary] Clinton and most Democrats will make it hard for him to lead the Dems in ’16,” Dan Pfeiffer, who served as Obama’s senior political adviser until leaving in February, wrote on Twitter. “The base won’t support a leader who thought Obamacare was a mistake and wants War with Iran,” he wrote in another tweet.

Schumer has previously criticized the timing of passing Obama’s Affordable Care Act as a political mistake. Despite the White House reaction, Schumer maintains broad support among his colleagues, and there is no indication that his expected ascension to Senate minority leader is in jeopardy.

Schumer, who is Jewish, said he had decided not to support the agreement out of concern that it would strengthen Iran by boosting its economy and ultimately may not prevent the country from developing a nuclear bomb.

Obama publicity blitz

The attacks on Schumer were part of a forceful campaign by Obama to defend the Iran deal.

The president has pledged to veto any bill rejecting the accord, which would lift economic sanctions against Iran and require the country to dismantle much of its nuclear infrastructure.

He has bluntly confronted his opponents, including Republicans, Jewish American leaders and Israeli Prime Minister Benjamin Netanyahu, stating that they would prefer war over a diplomatic solution to contain Tehran’s nuclear ambitions.

Obama has also launched a publicity blitz that has included a major speech at American University, a private two-hour session at the White House with two-dozen Jewish American leaders, and an on-the-record chat with nine ­foreign-policy columnists. It will culminate with an interview with CNN’s Fareed Zakaria that will air Sunday.

Republicans have chided Obama for his harsh tone, and House Speaker John A. Boehner (R-Ohio) on Friday said Obama’s attacks on opponents amounted to “slander.”

But Earnest stood by Obama’s contention that Republicans had made “common cause” with Iranian hard-liners who opposed the deal.

“It was a statement of fact,” Earnest said this week. Asked whether Democrats who are calling on Obama to seek a better deal with Iran are “pursuing a fantasy,” as Obama had accused Republicans, Earnest replied: “The suggestion that there is a better deal is a fantasy. The president stands by those remarks entirely.”

Obama has countered that his critics have used unfair and misleading arguments to rally opposition. During the private White House meeting with Jewish American leaders, the president suggested that his opponents tone down their rhetoric if they wanted him to do the same, according to several participants. Obama was particularly irked by the American Israel Public Affairs Committee’s $20 million ad campaign against the plan.

One participant, speaking on the condition of anonymity to discuss a private conversation, said Obama argued “that this would not be as big an issue and as big a fight if basically the pro-Israel community was not making it into a big fight. . . . So essentially the takeaway was that he was broadly asking the organizations to consider stepping back.”

Seeking a close victory

Schumer is expected to take over from retiring Sen. Harry M. Reid (Nev.) as the leader of the Senate Democrats after the next election cycle. His independence from the West Wing has made him a target at times for liberal activists. But he is a respected figure inside the Democratic caucus and clinched the race to succeed Reid within hours of the leader’s announcement that he would retire.

Schumer’s long wait to announce his opposition to the Iran deal — more than three weeks after it was formally sent to Congress — left an opening that was filled by a steady stream of announcements of support from other senior Democrats. Sens. Tammy Baldwin (Wis.) and Bernie Sanders (I-Vt.) on Friday became the 14th and 15th members of the Democratic caucus in the Senate to publicly support the deal.

Sens. Dianne Feinstein (Calif.) and Barbara Boxer (Calif.), the most senior Jewish Democrats in the Senate, both backed the deal. Sen. Bill Nelson (D-Fla.) had been a target for opponents of the accord, in part because his state is home to powerful Jewish figures. Instead, in a floor speech Tuesday, Nelson embraced the pact.

The deal has also won critical backing from a new generation of Democrats who have raised their profile by focusing on global ­affairs: First-term Sens. Timothy M. Kaine (Va.), a potential vice presidential pick for 2016, and Chris Murphy (Conn.).

In addition to Schumer, Sen. Robert Menendez (D-N.J.) has been highly critical and is expected to oppose the deal.

The administration will be happy if it gets just enough support to be able to uphold a veto and is not seeking a large margin, a White House official said. The aide said that a close victory would suffice and that the administration is not trying to get enough votes to filibuster and prevent a Senate vote.

Rep. Adam B. Schiff (Calif.), who is the top Democrat on the House Select Committee on Intelligence and who announced his support for the deal last week, said Schumer’s decision “doesn’t change the dynamic that much.”

“The only surprise may have been the timing,” Schiff said.“I think many people thought he may have waited longer than he did.”

The timing will allow well-funded deal opponents to tout Schumer’s opposition in a month’s worth of television ads. But there is little sign thus far that Schumer himself intends to participate in a broader public relations campaign against the deal.

“There are some who believe that I can force my colleagues to vote my way,” Schumer said in a statement Thursday. “In my experience with matters of conscience and great consequence like this, each member ultimately comes to their own conclusion.”

Mike DeBonis and Steven Mufson contributed to this report.