It’s the second vote in as many days, after the Senate defeated a similar measure along party lines. Lawmakers are confronting the sudden reality of representing wary Americans in wartime and all that entails — with lives lost, dollars spent and alliances tested by a president’s unilateral decision to go to war with Iran.

While the tally in the House, 212-219, was expected to be tight, the outcome provided a clarifying snapshot of political support for, and opposition to, the U.S.-Israel military operation and Trump’s rationale for bypassing Congress, which alone has the power to declare war. At the Capitol, the conflict has quickly carried echoes of the long wars in Afghanistan and Iraq, and many Sept. 11-era veterans now serve in Congress.

“Donald Trump is not a king, and if he believes the war with Iran is in our national interest, then he must come to Congress and make the case,” said Rep. Gregory Meeks, the top Democrat on the House Foreign Affairs Committee.

The House also approved a separate measure affirming that Iran is the largest state sponsor of terrorism.

Republicans largely back Trump, and most Democrats oppose the war

Trump’s Republican Party, which narrowly controls the House and Senate, largely sees the conflict with Iran not as the start of a new war, but the end of a government that has long menaced the West. The operation has killed Iran’s Supreme Leader Ayatollah Ali Khamenei, which some view as an opportunity for regime change, though others warn of a chaotic power vacuum.

Republican Rep. Brian Mast of Florida, chairman of the House Foreign Affairs Committee, publicly thanked Trump for taking action against Iran, saying the president is using his own constitutional authority to defend the U.S. against the “imminent threat” the country posed.

Mast, an Army veteran who worked as a bomb disposal expert in Afghanistan, said the war powers resolution was effectively asking “that the president do nothing.”

For Democrats, Trump’s attack on Iran, influenced by Israeli Prime Minister Benjamin Netanyahu, is a war of choice that is testing the balance of powers in the Constitution.

“The framers weren’t fooling around,” said Rep. Jamie Raskin, D-Md., arguing that the Constitution is clear that only Congress can decide matters of war. “It’s up to us.”

While views in Congress are largely falling along party lines, there are crossover coalitions. The war powers resolution, if signed into law, would have immediately halted Trump’s ability to conduct the war unless Congress approved the military action. The president would likely veto it.

Trump officials provide shifting rationale for war

After launching a surprise attack against Iran on Saturday, Trump has scrambled to win support for a conflict that Americans of all political persuasions were already wary of entering. Trump administration officials spent hours behind closed doors on Capitol Hill this week trying to reassure lawmakers that they have the situation under control.

Six U.S. military members were killed over the weekend in a drone strike in Kuwait, and Trump has said more Americans could die. Thousands of Americans abroad have scrambled for flights, many lighting up phone lines at congressional offices as they sought help trying to flee the Middle East.

Trump said Thursday he must be involved in choosing Iran’s new leader. Yet House Speaker Mike Johnson, R-La., said this week that America has enough problems at home and is not about to be in the “nation-building business.”

Defense Secretary Pete Hegseth said that the war could extend eight weeks, twice as long as the president first estimated. Trump has left open the possibility of sending U.S. troops into what has largely been a bombing campaign by air. More than 1,230 people in Iran have died.

The administration said the goal is to destroy Iran’s ballistic missiles that it believes are shielding its nuclear program. It has also said Israel was ready to act, and American bases would face retaliation if the U.S. did not strike Iran first. On Wednesday, the U.S. said it torpedoed an Iranian warship near Sri Lanka.

“This administration can’t even give us a straight answer of as to why we launched this preemptive war,” said Rep. Thomas Massie, the Republican from Kentucky, an outlier in his party.

Massie and Rep. Ro Khanna, D-Calif., who had teamed up to force the release the Jeffrey Epstein files, also pushed the war powers resolution to the floor, past objections from Johnson’s GOP leadership. Another Republican, Rep. Warren Davidson of Ohio, a former Army Ranger, was also expected to back the war powers resolution.

Johnson has warned that it would be “dangerous” to limit the president’s authority while the U.S. military is already in conflict.

“Congress must stand with the president to finally close, once and for all, this dark chapter of history,” said Rep. Michael McCaul, R-Texas.

Rep. Yassamin Ansari, D-Ariz., said that as the daughter of Iranian immigrants who fled their homeland, she celebrates Khamenei’s death. But she warned that a democratic transition for the people of Iran never seems to a priority for Trump and his officials who briefed lawmakers.

“War carries profound and deadly consequences for our troops, for the American people and for the entire world,” she said. “It’s the most serious decision that a nation can make and the American people deserve debate, transparency and accountability before that decision is made.”

Other Democrats have proposed an alternative resolution that would allow the president to continue the war for 30 days before he must seek congressional approval. It is not expected yet for a vote.

Senators sit in their desks for solemn vote

In the Senate, Republican leaders have successfully, though narrowly, defeated a series of war powers resolutions pertaining to several other conflicts during Trump’s second term. This one, however, was different.

Underscoring the gravity of the moment Wednesday, Democratic senators filled the chamber and sat at their desks as the voting got underway.

Senate Democratic leader Chuck Schumer of New York said before the vote that every senator will pick a side. “Do you stand with the American people who are exhausted with forever wars in the Middle East or stand with Donald Trump and Pete Hegseth as they bumble us headfirst into another war?”

Sen. John Barrasso, second in Senate Republican leadership, said “Democrats would rather obstruct Donald Trump than obliterate Iran’s national nuclear program.”

The legislation failed on a 47-53 tally mostly along party lines, with Sen. Rand Paul, R-Ky., in favor and Sen. John Fetterman, D-Pa., against it.

[This headline has been updated to correct that the resolution narrowly failed.]