Democratic Party Chairwoman Debbie Wasserman Schultz said on Sunday that she would vote for the nuclear agreement with Iran, ending speculation about whether a top party leader would support President Barack Obama on the agreement.
Mrs Wasserman Schultz's 23rd district in Florida is heavily Jewish.
However, another Democratic Jewish congresswoman representing Florida - Lois Frankel, whose district includes West Palm Beach - came out against the deal.
Congress is expected to vote on the deal as early as this week.
