Democrats in the U.S. Senate on Thursday defeated for the third time a Republican-backed resolution that sought to disapprove President Barack Obama’s historic deal curbing Iran’s development of nuclear weapons.

As in previous votes, Hawaii Sens. Brian Schatz and Mazie Hirono voted “nay” on the measure, this one a 56-to-42 vote.

Thursday was the deadline for congressional action on the Iran deal.

Even though the U.S. House of Representatives has rejected it, the Senate’s failure means that the agreement is a done deal. The GOP fell short of the 60 votes required to advance the Senate measure.

Democrats also blocked a Republican effort to stop the Iran nuclear deal “by linking the agreement to Israel and American prisoners,” says The Hill.

The 53-to-45 vote on the amendment was also opposed by Schatz and Hirono.

Skipping both votes were Republicans Marco Rubio of Florida and Rand Paul of Kentucky. Both are running for president.