White House hopes for stopping a congressional challenge to the Iran nuclear deal suffered a blow when a key Senate Democrat announced his opposition on September 4.
Senator Ben Cardin, top Democrat on the Foreign Relations Committee, said he will vote against the deal because it "legitimizes Iran's nuclear program" and would allow Iran to develop a nuclear weapon within 10 to 15 years.
Cardin's opposition doesn't change the ultimate outcome in Congress, where the accord is still likely to be upheld despite unanimous opposition from the Republican majority. It just means the president will have to use his veto to protect it from defeat in Congress.
The White House already has enough votes in the Senate to prevent Republicans from overriding a veto.
But the White House had started aiming for a more ambitious goal as momentum in favor of the accord grew among Democrats last month: blocking the Republicans' disapproval resolution from ever reaching the president's desk using parlimentary techniques that can be carried out with the support of 41 Democrats in the Senate.
With Cardin's announcement, that goal remains in reach, but it will be tougher to attain.