The Senate voted down a war powers resolution on Iran on Thursday, September 24, 2026, by 49 to 50 — one vote short of passage, and the closest Congress has come to forcing an end to the seven-month air campaign.
The measure would have required President Trump either to terminate military operations against Iran or to come back to Congress for authorization. It had already passed the House.
How the chamber split
Four Republicans voted with the Democrats: Susan Collins of Maine, Rand Paul of Kentucky, Thom Tillis of North Carolina and Lisa Murkowski of Alaska. For Tillis it was a first — he had not previously supported a measure to end the Iran conflict.
One Democrat, John Fetterman of Pennsylvania, voted against, consistent with his position on earlier versions.
The arithmetic turned on an absence as much as on the crossovers. Senator Angela Alsobrooks of Maryland did not vote. Had she been present and voted yes, the chamber would have tied at 50-50 — and the tiebreak would have gone to Vice President JD Vance, who presides over the Senate.
In the House, seven Republicans had backed the resolution, the strongest Republican support any Iran war-ending measure has drawn there.
Congress has already voted once, and been ignored
This was not the first time both chambers were asked the question. In June 2026 the House and Senate passed a concurrent war powers resolution directing the president to end hostilities against Iran. The White House did not comply, arguing the measure infringed on the president's authority as commander-in-chief.
The War Powers Act of 1973 states that American forces "shall be removed by the President if the Congress so directs by concurrent resolution." That June resolution remains on the books. Representative Thomas Massie has argued that continuing the operation violates the act, since Congress has neither declared war on Iran nor authorized the conflict.
By the count kept since the bombing began on February 28, the Senate has now taken up fourteen Iran war powers resolutions and approved two.
Why the vote was scheduled now
The timing is electoral as well as constitutional. With midterm elections in November, Democrats wanted Republicans on the record on a war that polls badly — approval of the strikes on Iran stood at 34 percent in survey work cited during the debate — and one whose effects reach voters through food and fuel prices.
The underlying disagreement has not moved. Democrats argue the Constitution assigns the power to commit the country to war to Congress. Republicans argue the commander-in-chief clause covers what the administration is doing.
What changed on Thursday is only the margin. One vote is a narrower result than the White House has faced on Iran so far, and the resolution's sponsors can bring it back.
Reporting from The National, Democracy Now! and Antiwar.com.
