President Donald Trump publicly reprimanded four Republican senators who voted to block his ability to restart hostilities with Iran, highlighting a significant division between the White House and the Republican-controlled Senate during his second term. The motion, which passed the Senate 50-48 on Tuesday, seeks to limit the president’s military engagement with Iran without explicit congressional authorization.

On his social media platform, Truth Social, Trump accused the dissenting senators of undermining his efforts against Iran, which he said was “on the ‘ropes,’ ready to go down for the fall.” He referred to the senators as “four Republican Losers” and vowed to carry out his agenda “one way or the other.” The bipartisan resolution, which had already been approved by the House earlier this month, invokes the War Powers Resolution of 1973, a law that requires presidents to obtain congressional approval before prolonged military action.

Two other Republicans, Senate Minority Leader Mitch McConnell of Kentucky and Dave McCormick of Pennsylvania, were absent for the vote. Pennsylvania Democrat John Fetterman joined Republicans in opposing the measure.

The senators who broke ranks with Trump did so citing constitutional concerns about Congress’s role and the need for clear objectives and oversight in military actions. Senator Susan Collins of Maine expressed that presidential authority as commander-in-chief has limits and emphasized the War Powers Act’s 60-day deadline for authorizing or ending hostilities is mandatory, not optional. She has consistently voted with Democrats on this issue since it became evident that the deadline would be exceeded without congressional approval.

Senator Bill Cassidy of Louisiana, who has a history of opposing Trump—including voting to convict him in the 2021 impeachment trial—aligned with Democrats after losing a Republican primary runoff in his state earlier this year. He acknowledged support for curbing Iran’s nuclear development but criticized the administration for lack of transparency and cited constituent concerns about the ongoing conflict. He also denounced the recent ceasefire deal, calling it a major foreign policy misstep that leaves Iran’s nuclear ambitions unchecked.

Alaskan Senator Lisa Murkowski initially opposed efforts to restrict strikes against Iran but reversed course after the War Powers deadline passed, advocating for congressional involvement and oversight. She argued that ongoing U.S. military activity in the region contradicts claims that the conflict has ended and stressed the need for the administration to seek congressional authorization before further engagement. Murkowski pointed to the economic impact on her state, where rising energy costs have been exacerbated by tensions in the Strait of Hormuz.

Senator Rand Paul of Kentucky was the sole Republican to support the initial resolution blocking further strikes and has consistently criticized prolonged U.S. military involvement abroad. He defended the ceasefire deal and urged serious diplomatic efforts as a preferable alternative to regime collapse, which he warned could lead to instability and new threats.

The White House maintains that the War Powers Resolution is outdated and constitutionally questionable, arguing that the conflict has concluded and congressional approval is not required. However, Democrats and some Republicans disagree on the legal and practical enforceability of the Senate measure, reflecting ongoing debates over the balance of war powers between Congress and the president.