The Senate voted overwhelmingly Thursday to approve legislation allowing Congress to review a nuclear deal with Iran in a 98-1 vote.
Sen. Tom Cotton (R-Ark.) was the only senator to oppose the bill. He said in a statement that he objected that the deal was not to be presented to the Congress as a treaty.
"A nuclear-arms agreement with any adversary—especially the terror-sponsoring, Islamist Iranian regime—should be submitted as a treaty and obtain a two-thirds majority vote in the Senate as required by the Constitution," he said.
A vote to disapprove a nuclear deal with Iran would not kill it. President Obama could veto such a measure, and the House and Senate would then need two-thirds majorities to override his veto.
The administration initially opposed the legislation, arguing it could interfere with negotiations with Iran. The White House changed course after it became clear that the bill had strong support from Democrats.
Republicans also expressed frustrations that they could not offer more amendments to the bill.
Senate GOP Leader Mitch McConnellMitch McConnellSenate confirms first nominees of Trump era The new Washington elite schmoozes over lunch Trump takes first official acts at signing ceremony MORE (R-Ky.) filed a motion to end debate after Sens. Marco RubioMarco RubioGOP, Dems hear different things from Trump Senate committee to vote Monday on Tillerson Tillerson met with top State official: report MORE (R-Fla.) and Cotton tried to force a vote on an amendment requiring Iran to recognize Israel's right to exist as part of a final deal.
The move was a reversal of the open amendment process Republican leadership pledged to bring to the Senate.
McConnell said Thursday that he would have preferred that amendments be added to the bill, but that it might have invited a presidential veto.
“If we didn’t face the threats of filibusters, or the blocking of amendments, or the specter of presidential vetoes, this bill would be a heck of a lot stronger. I assure you,: he said. “But the truth is, we do. That’s the frustrating reality.”
Rubio slammed the decision not to allow his amendment requiring Iran to support Israel as part of a deal to come up for a vote, saying that some senators are "terrified" of voting against it.