Senate Majority Leader Mitch McConnell moved Tuesday evening to end debate on an Iran review bill, shortening what he had hoped would be an open amendment process out of concern that some "poison pill" votes coul potentially sink the bipartisan compromise.
Both Republicans and Democrats had been predicting McConnell would make this move since last week, when proposed amendments by GOP Sens. Marco Rubio and Tom Cotton raised the ire of Senate Foreign Relations Committee Chairman Bob Corker and panel ranking member Ben Cardin. McConnell had kept his cards close to the vest, apparently trying through Monday night to figure out some kind of compromise.
Corker's bill would give Congress a role in reviewing any U.S.-Iran agreement on the Iranian nuclear program, but some foreign policy hawks want the bill to be more strict. Rubio is pushing for a requirement that Iran recognize Israel's right to exist, while Cotton wants Iran to reveal the history of its nuclear program. Yet the addition of such amendments could have prompted the White House—which had agreed to the Corker-Cardin compromise—to threaten a veto.
Corker remained frustrated Tuesday that last week's proposed amendments had short-circuited the process.
"The procedural moves Thursday certainly ended our discussions that were going in a very constructive and positive way relative to the amendments," Corker said. "Sometimes people forget that the Senate operates by unanimous consent."
Corker said he was trying to get some consensus items in a managers' package and maybe an agreement with Democrats for some amendment votes. But he acknowledged that "Democrats don't have much incentive here to negotiate."
Corker predicted that the chamber would soon be able to move forward again on the bill with bipartisan backing. "My sense is that Thursday, there's a very good chance that we'll have an overwhelming vote," he said.
This article has been updated.
Alex Rogers covers Congress as a staff correspondent for National Journal. He previously worked as a political reporter at TIME. He is a native of Bethesda, Maryland and a graduate of Vanderbilt University.