Story Highlights
- The Senate passed a war powers resolution 50-48 on Tuesday, the first time both chambers of Congress have passed such a resolution since the U.S.-Iran war began in February 2026
- Four Republican senators — Bill Cassidy, Lisa Murkowski, Susan Collins, and Rand Paul — crossed party lines to vote with Democrats on the initial resolution
- Senate Republicans rejected a procedurally similar measure the following night after Trump met privately with GOP senators and publicly labeled the four dissenting Republicans “losers”
What Happened
The United States Senate voted 50-48 on Tuesday, June 24, to pass a war powers resolution directing President Donald Trump to remove American armed forces from hostilities against Iran unless explicitly authorized by a formal declaration of war or a specific congressional authorization for the use of military force. The resolution, which had already cleared the House of Representatives by a vote of 215-208 earlier this month, marked the first time both chambers of Congress had successfully passed such a measure since the U.S.-Israel military campaign against Iran began on February 28.
Four Republican senators broke with their party to vote in favor: Bill Cassidy of Louisiana, Lisa Murkowski of Alaska, Susan Collins of Maine, and Rand Paul of Kentucky. The lone Democrat to oppose the resolution was John Fetterman of Pennsylvania. Two Republicans, Mitch McConnell of Kentucky and Dave McCormick of Pennsylvania, did not vote. Trump responded almost immediately on Truth Social, calling the four Republicans “losers” who had “provided aid and comfort to the Enemy” and made his job “more difficult.” He argued the vote was poorly timed, coming as his envoys were engaged in negotiations with Iran in Switzerland.
The following day, Trump traveled to the Capitol to meet with Republican senators at a closed-door lunch. Invited by Florida Senator Rick Scott, Trump was expected to discuss the SAVE America Act voting bill, but the conversation quickly turned to the war powers vote. By multiple accounts, Trump harangued senators, exchanging particularly heated words with Cassidy. Cassidy stood and defended his vote, telling reporters afterward that he told Trump the American people had not been adequately informed about the war’s objectives. “You have not told the American people what’s going on,” Cassidy said he told the president.
That same night, the Senate held a late vote on a procedurally separate but substantively similar war powers measure, this time rejecting it. Cassidy and Paul changed their votes — Paul voting present and Cassidy voting against advancing the new resolution — while Collins and Murkowski again voted to advance it. The reversal gave Trump a political win he quickly celebrated, posting on social media that the vote “puts Iran on notice.” Vice President JD Vance and envoy Steve Witkoff later hosted Cassidy at the White House for a personal briefing on the Iran conflict.
Why It Matters
The initial passage of the war powers resolution, even in its nonbinding form, represents a milestone in congressional scrutiny of the Iran war. It was the tenth time the Senate had voted on a war powers measure related to the conflict, and the first time one cleared the simple majority threshold. The vote reflected growing unease not only among Democrats but within the Republican caucus itself, particularly as the war’s popularity with the broader American public has declined sharply. A Reuters/Ipsos poll released on the day of the vote found that only 24 percent of Americans believed the war had been worth its cost.
The rapid reversal the following day, however, also tells a revealing story. Despite genuine misgivings about the war’s strategy and endgame, most Republican senators ultimately chose party loyalty and deference to Trump over exercising independent legislative authority. Only Collins and Murkowski maintained consistent votes on both days. The episode illustrates the enormous social and political pressure Trump exerts over his caucus even when that caucus harbors substantive policy disagreements with him.
The war powers debate also intersects with a broader constitutional question about the distribution of authority over military engagement. The last formal congressional declaration of war was during World War II. Since then, successive administrations have relied on authorizations for the use of military force or claimed inherent executive authority to commit forces abroad. Trump has been explicit about his view that his war-making powers face no meaningful limits, a posture that conflicts with the text of the Constitution and that congressional Republicans have largely accepted in practice even while voicing reservations in private.
The midterm elections loom over every calculation. Republican senators are acutely aware that the Iran war’s unpopularity could become a liability in competitive states, and that voters will be watching whether Congress exercised any meaningful oversight. The tension between accountability and loyalty will likely intensify as November approaches and the war’s costs — financial, military, and diplomatic — continue to accumulate.
Economic and Global Context
The U.S.-Iran war, which began with airstrikes on February 28, has generated significant economic ripple effects across global energy and financial markets. Iran is a major oil producer, and the conflict has introduced sustained uncertainty into crude supply chains. The Strait of Hormuz, through which roughly a fifth of the world’s oil supply transits, has been a focal point of tension, with U.S. complaints about allied involvement in efforts to reopen it generating friction within NATO.
The cost of the military campaign itself remains difficult to fully assess from public information, but defense spending has been a growing line item in congressional appropriations debates. Republican senators like John Cornyn and Armed Services Committee Chairman Roger Wicker have pushed back against aspects of Trump’s 14-point memorandum of understanding with Iran, suggesting concern within the GOP about the war’s terms and trajectory.
Switzerland negotiations between U.S. and Iranian representatives have been the primary diplomatic track, and the war powers vote landed at a sensitive moment in those discussions. Supporters of the resolution argued it put appropriate pressure on both sides to reach a settlement. Critics, including Senator James Risch of Idaho, warned that it signaled weakness to Tehran and risked unraveling whatever progress had been made.
Implications
The most immediate implication is that the Iran war will continue with limited formal congressional constraint, at least for now. The nonbinding nature of the resolutions means Trump is under no legal obligation to change his military posture, and his administration has questioned the constitutionality of the War Powers Act itself. The likelihood of Congress passing a binding restriction, let alone overriding a presidential veto, remains extremely low given current vote counts.
For Republican senators, the episode deepens a difficult dynamic heading into the fall. Those who voted against Trump once and then reversed under pressure may face criticism from both sides — from the left for ultimately capitulating and from Trump loyalists for having broken ranks at all. Both Cassidy and Paul, who have grown more critical of Trump since losing or choosing not to seek reelection, face ongoing political consequences in the form of administration hostility and potential endorsements of primary challengers.
For the American public, the Senate drama underscores how difficult it remains to exercise congressional war powers oversight in the modern political environment. Even when a majority exists for a symbolic rebuke, the social pressure of a single lunch can reverse it by the following evening. The war will likely remain a central electoral issue through November, testing whether voters reward or punish the party that launched and sustained it.
Sources
“Senate Republicans reject war powers resolution after Trump berates them at Capitol meeting”
