WASHINGTON – Hours after US Sen. Charles Schumer (D-New York) announced that he would vote against the Iran nuclear agreement, another Jewish Democratic member of Congress, Rep. Brad Sherman of California, said on Friday he would follow suit.Sherman, the second ranking Democrat on the House Foreign Affairs Committee, said that after reviewing details of the deal, his conscience forced him to vote against his party’s president.“My efforts have one purpose – make it clear that future presidents and Congresses are not bound by this agreement,” Sherman said. “Not legally, not morally, not diplomatically.”Schumer, the most senior Jewish member of the US Congress and likely the next Democratic leader of the Senate, on Thursday, declared his intention to oppose the deal reached last month.His declaration in opposition was the first from the Senate Democratic caucus and is considered influential by his peers. A plurality of Democrats remain undeclared on a pending vote of disapproval over the Joint Comprehensive Plan of Action, while 15 members of the Senate have declared their support.The JCPOA, the formal name for the Iran nuclear accord, is intended to cap, restrict, monitor and partially roll back Iran’s nuclear program for a finite period in exchange for sanctions relief. Skeptics of the deal fear it will legitimize Iran as a nuclear threshold state, allowing it to retain an ever-growing uranium enrichment program.“I have decided I must oppose the agreement and will vote ‘yes’ on a motion of disapproval,” Schumer said in a statement. “The agreement would allow Iran, after 10 to 15 years, to be a nuclear threshold state with the blessing of the world community.”“To me,” he added, “the very real risk that Iran will not moderate and will, instead, use the agreement to pursue its nefarious goals is too great.”The decision by Schumer was “disappointing but not surprising,” White House spokesman Josh Earnest said on Friday.Earnest told reporters the Obama administration worked closely with Schumer to explain details of the deal even before it was signed in an effort to gain his support.“Ultimately, it didn’t turn out that way. I don’t think anybody was surprised,” Earnest said.Schumer’s colleague from New York, Senator Kirsten Gillibrand, announced her intentions to vote in favor of the deal earlier on Thursday.Congressman Eliot Engel (D-New York), ranking member of the House Foreign Affairs Committee and a senior Jewish member, also declared his opposition to the agreement.“The answers I’ve received simply don’t convince me that this deal will keep a nuclear weapon out of Iran’s hands, and may in fact strengthen Iran’s position as a destabilizing and destructive influence across the Middle East,” Engel said. He joins four other Democratic lawmakers from New York House of Representatives who are opposed.US President Barack Obama is struggling to gain congressional backing for the deal, which lawmakers must vote on by September 17. Schumer’s rejection means the Obama administration may have to ramp up its lobbying efforts on Capitol Hill.The administration is confident it can continue to build support before next month’s deadline, he added.A spokesman for Senator Dick Durbin of Illinois, who counts Democratic votes as the Senate’s minority whip and who supports the deal, said Democrats were still confident they could rebuff Republican attempts to sink the agreement in a showdown next month.“The momentum is behind this deal, as you’ve seen from Democrats coming out this week,” spokesman Ben Marter said.So far, at least 14 Senate Democrats and independents who vote with Democrats and about 34 House Democrats have announced they would back the deal. There are 46 members of the Democratic caucus in the 100-member Senate and 188 Democrats in the 435-member House.Most Republicans have already said they are opposed, as have a handful of House Democrats.Jerusalem Post staff and Reuters contributed to this report.