U.S. President Barack Obama’s hopes of preserving the nuclear deal between Iran and world powers were dealt a setback on Thursday when Chuck Schumer, one of the top Democrats in the U.S. Senate, said he would the oppose the agreement. Schumer’s opposition, announced in a lengthy statement, could pave the way for more of Obama’s fellow Democrats to come out against the nuclear pact announced on July 1 between the United States, five other world powers and Iran. The New York senator is among the most influential Jewish lawmakers in the United States. He was the first Senate Democrat to announce his opposition to the agreement. Another influential Jewish lawmaker, U.S. Representative Eliot Engel, the top Democrat on the House of Representatives Foreign Affairs Committee, also said on Thursday he would oppose the nuclear pact in a statement obtained by Reuters.