For the second time in as many weeks, Senate Democrats blocked a procedural vote to move forward with a resolution of disapproval of the Iran nuclear deal negotiated by the Obama administration and five other world powers with Tehran.

With a 56-42 vote, the Republican-led Senate failed to get the 60 votes needed to advance the legislation, just as it did last Thursday, reports Reuters.

Republicans had hoped they could convince a few more Democrats to vote for the resolution of disapproval the second go-around, and also to use the vote to make political points against Democrats in future Senate races, according to The Associated Press. They cited polls showing Americans have concerns about the deal.

Senate Majority Leader Mitch McConnell (R-Ky.) criticized Democratic senators for refusing to even let the issue proceed to an up-or-down vote.

"A strong, bipartisan majority of the House of Representatives voted to reject the deal. A strong, bipartisan majority of the Senate would vote to reject the deal too," McConnell said, according to AP. "If only Democrat senators would stop blocking the American people from even having a final vote on one of the most consequential foreign policy issues of our age."

Refusing to let the issue die quietly, McConnell set up a third procedural vote for Thursday on an amendment that would bar Obama from lifting economic sanctions against Iran until Tehran formally recognizes Israel's right to exist and also releases U.S. prisoners currently held in Iran.

"I will file on an amendment that would prevent the president from lifting sanctions until Iran meets two simple benchmarks: It must formally recognize Israel's right to exist, and it must release the American citizens being held in Iranian custody," he said before the roll call, reported The Huffington Post.

"Either way this debate will continue," he said. "Democrats seem to think they can end the discussion by blocking an up-or-down vote, then turn around and pretend they care deeply about Israel and human rights. Well if they vote again to deny the American people a final vote, they'll have a chance to test the theory."

It's not yet clear how Democrats will line up on such a politically fraught measure, but The Associated Press speculates they will be able to block that measure as well.