The Senate voted Wednesday to repeal the resolution that gave a green light for the 2003 invasion of Iraq, an effort to return a basic war power to Congress from the White House 20 years after an authorization many now say was a mistake.

Iraqi deaths are estimated in the hundreds of thousands, and nearly 5,000 U.S. troops were killed in the war after President George W. Bush’s administration falsely claimed that Saddam Hussein was stockpiling weapons of mass destruction.

“This body rushed into a war,” said Virginia Sen. Tim Kaine, a Democrat who has pushed for years to repeal the powers. The war has had “massive consequences,” Kaine said.

Senators voted 66-30 to repeal the 2002 measure and also the 1991 authorization that sanctioned the U.S.-led Gulf War. If passed by the House, the repeal would not be expected to affect any current military deployments. But lawmakers in both parties are increasingly seeking to claw back congressional powers over U.S. military strikes and deployments, and some lawmakers who voted for the Iraq War two decades ago now say that was a mistake.

“Americans want to see an end to endless Middle East wars,” said Senate Majority Leader Chuck Schumer, adding that passing the repeal “is a necessary step to putting these bitter conflicts squarely behind us.”

Supporters, including almost 20 Republican senators, say the repeal is crucial to prevent future abuses and to reinforce that Iraq is now a strategic partner of the United States. Opponents say the repeal could project weakness as the U.S. still faces conflict in the Middle East.

“Our terrorist enemies aren’t sunsetting their war against us,” said Senate Republican leader Mitch McConnell, who is at home recovering from a fall earlier this month and missed the vote. “When we deploy our servicemembers in harm’s way, we need to supply them with all the support and legal authorities that we can.”

The repeal’s future is less certain in the House, where 49 Republicans joined with Democrats in supporting a similar bill two years ago. House Speaker Kevin McCarthy, R-Calif., has suggested he is open to supporting a repeal even though he previously opposed it, but Rep. Michael McCaul of Texas, the Republican chairman of the House Foreign Affairs Committee, has indicated he would like to instead replace it with something else. But it is unclear what that would be.

Kaine and Todd Young, R-Ind., who led the effort together, have said they believe a strong bipartisan vote sends a powerful message to Americans who believe their voices should be heard on matters of war and peace.

President Donald Trump’s administration cited the 2002 Iraq war resolution as part of its legal justification for a 2020 U.S. drone strike that killed Iranian Gen. Qassim Soleimani, but the two war powers resolutions have otherwise rarely been used as the basis for any presidential action. About 2,500 U.S. troops remain in Iraq at the invitation of the Iraqi government and assist and advise local forces.

A separate 2001 authorization for the global war on terror would remain in place under the bill, which President Joe Biden has said he will support.

The October 2002 votes to give Bush broad authority for the Iraq invasion were a defining moment for many members of Congress as the country debated whether a military strike was warranted. The U.S. was already at war then in Afghanistan, the country that hosted the al-Qaida plotters responsible for the Sept. 11, 2001, attacks, something Iraq played no part in.

False Intelligence Cited to Justify Invasion

The Bush administration had drummed up support among members of Congress and the American public for invading Iraq by promoting what turned out to be false intelligence alleging Saddam had weapons of mass destruction. After the initial March 2003 invasion, American ground forces quickly discovered that the allegations of nuclear or chemical weapons programs were baseless.

The U.S. overthrow of Iraq’s security forces precipitated a brutal sectarian fight and violent campaigns by Islamic extremist groups in Iraq. Car bombings, assassinations, torture and kidnapping became a part of daily life for years.

Some GOP senators opposing the repeal, including McConnell, have raised concerns about recent attacks against U.S. troops in Syria. A drone strike last week killed an American contractor and wounded five troops and another contractor, then a rocket attack wounded another service member. Iranian-backed militants are believed responsible for the attacks.

Biden and his administration have argued that the repeal would not affect any response to Iran. Defense Secretary Lloyd Austin and Army Gen. Mark Milley, chairman of the Joint Chiefs of Staff, both said at a Senate hearing last week that American troops are authorized to protect themselves and respond to attacks, including under Article 2 of the Constitution, which gives the president the authority to protect troops.

The pushback from McConnell comes amid a growing rift in the Republican Party on the U.S. role in the Middle East, with some echoing Trump’s “America First” message to argue against military intervention abroad. Other Republicans are concerned Congress is giving too much leeway to the president in matters of war.

“I think a lot of lessons have been learned over the last 20 years,” said Young, the Indiana senator who is the lead Republican sponsor of the repeal. He said that those supporting the legislation “want to ensure that the American people can hold us accountable, rather than delegating those important authorities to an executive branch and then lamenting the unwitting wisdom of the executive branch if things don’t go well.”

This story has been updated.