Senate passes Iran war powers resolution in bipartisan rebuke to Trump

The Senate approved a bipartisan Iran war powers resolution on Tuesday by a 50-48 vote, putting four Republicans on record with Democrats in the first measure of its kind to pass both chambers of Congress. The concurrent resolution, which does not require President Donald Trump’s signature and cannot by itself become law, directs the president to remove U.S. armed forces from hostilities against Iran unless Congress declares war or grants military authorization.

Bill Cassidy of Louisiana, Susan Collins of Maine, Rand Paul of Kentucky and Lisa Murkowski of Alaska joined most Democrats in support. John Fetterman of Pennsylvania voted no, while Mitch McConnell and Dave McCormick did not vote. The House had passed the same measure earlier in June with the same four Republicans breaking ranks, setting up a vote that underscored bipartisan frustration with a conflict that has stretched for months.

The White House has argued that U.S. forces are not currently engaged in hostilities and has also said the War Powers Resolution itself is unconstitutional. Trump intensified the clash after the House vote by attacking it on Truth Social as an effort to “limit my War Powers” during final negotiations with Iran. The Senate vote came as those negotiations continued, adding a political rebuke even as lawmakers acknowledged they had little immediate leverage over the military campaign.

The push also came after the legal clock lawmakers cite had already run. Trump formally notified Congress of the hostilities on March 2, 2026, starting the War Powers Resolution’s 60-day countdown for withdrawal absent congressional authorization. Critics said that deadline expired in May, turning the Senate vote into a test of whether Congress could still force a halt after the window had closed. This was the 10th Senate attempt to curb the war with Iran and the first to succeed on the floor.

The broader dispute has become a measure of Congress’s willingness to reassert authority over a war launched without explicit approval. Democratic sponsor Tim Kaine said 14 American troops had been killed, and Jules Hurst, the acting Pentagon comptroller, said the conflict had cost $29 billion so far. Gregory Meeks, the top Democrat on the House Foreign Affairs Committee, said he would explore all legal avenues to ensure executive compliance, while Senate Minority Leader Chuck Schumer pressed Republicans to support the effort publicly. Even if the administration resists, the vote marks the clearest congressional signal yet that support for the war has eroded across party lines.