After months of at times bitter debate, Democrats in the U.S. Senate used a filibuster on Thursday to block a Republican plan to derail the Iran nuclear agreement. It was a major setback for Congressional Republicans, as it cleared the way for a major foreign policy victory for President Obama.

"This vote is a victory for diplomacy, for American national security, and for the safety and security of the world," President Obama said in a written statement issued by the White House.

ajc.com

Credit: Jamie Dupree

icon to expand image

Credit: Jamie Dupree

"I am appalled that Senate Democrats are choosing to keep the people of the United States in the dark on where they stand on Iran by blocking an up-or-down vote on the president’s dangerous agreement with Iran," said Sen. Johnny Isakson (R-GA).

"We are making a terrible mistake," said Sen. Marco Rubio (R-FL), who had left the campaign trail in order to cast his vote for the effort to stop the Iran deal.

The vote was 58-42 to shut off debate; 60 votes were needed to end debate.

"This matter is over with," declared Senate Democratic Leader Harry Reid after the vote, urging Republicans not to revisit the issue in coming weeks and months.

ajc.com

Credit: Jamie Dupree

icon to expand image

Credit: Jamie Dupree

No GOP Senators broke ranks on the vote.

Republicans immediately filed another procedural motion to force a second vote on the matter - but the votes are not expected to change.