The Senate on Thursday, in a procedural move, cleared the way for a final vote on repealing decades-old war powers measures that authorized two wars with Iraq -- first under former President George H. W. Bush in the Gulf War, and then by his son, former President George W. Bush -- with supporters fearing that the outdated authorizations could be misused by a future president.
In a strong bipartisan showing, the Senate voted 67-27 in a test vote to repeal the authorizations.
It's now all but certain to pass the Senate in a final vote next week, but it's less clear is how a Republican-controlled House will handle the legislation.
Noting that the U.S. and Iraq are now security partners in the region, lead co-sponsor Democratic Sen. Tim Kaine of Virginia argued on Wednesday that it is long past time for Congress to reassert its constitutional authority to declare war, saying, "After 20 years, it's time to repeal this and show again that Congress can exercise that Article I muscle," referencing the war declaration powers spelled out in the Constitution.
Kaine, whose son is a Marine infantry officer, recalled being angered by what he called a rush to war in Iraq ahead of the 2002 midterm elections, when he was a lieutenant governor, and then later fought to get on the Senate Armed Services Committee and Foreign Relations Committee to repeal the two Iraq "AUMFs" -- or authorizations for the use of military force.
"Americans are tired of endless wars," said Senate Majority Leader Chuck Schumer, D-NY, Wednesday ahead of the debate.
He argued much the same Thursday, saying, "The nation of Iraq has changed dramatically since 2002, and it's time the laws on the books catch up with the changes. The Iraq war has itself been long over. This AUMF has outlived its purpose and we can no longer justify keeping it in effect."
Shortly before the Senate was set to vote, the White House weighed in with President Joe Biden's support.
"President Biden remains committed to working with the Congress to ensure that outdated authorizations for the use of military force are replaced with a narrow and specific framework more appropriate to protecting Americans from modern terrorist threats," it said in a statement.
The Senate Foreign Relations Committee last week voted 13-8 to repeal both the 1991 and 2002 Authorizations for the Use of Military Force (AUMF).
Schumer has confirmed that there will be votes on amendments next week before final passage. Kaine said he thought it likely that those would include the two GOP amendments rejected by the committee.
One -- by Republican Sen. Ted Cruz of Texas -- is at the core of GOP opposition to repeal. Some Republicans have argued that repealing the laws might risk sending a dangerous message in an ever volatile part of the world, particularly with regard to Iran. The top Republican on the committee -- Jim Risch of Idaho -- has repeatedly maintained that repealing the measures would send a message to Iran that the U.S. lacks resolve.
The Cruz amendment would affirm that the U.S. has the authority to attack Iran, though the committee last week rejected that measure 13-8.
GOP Sen. Todd Young, a lead sponsor of the repeal effort with Kaine and a Navy and Marine Corps veteran, argued that while he, too, shares his colleagues' concerns about Iran, a future administration should come to Congress and seek a specific approval for military action.
"I believe that the threat from Iran is so significant and so different from the wars since 9/11 or Saddam Hussain's Iraq, that we must pass a new AUMF should the situation require it," Young contended when the bill was first introduced. "Those advocating for leaving the 2002 AUMF in place as a means of deterring Iran, when that was in no way the intention of this authorization, would be building on past abuses and advocating for precisely the kind of expansion of war power authorities that ultimately makes Congress and this committee irrelevant."
And the chairman of the panel, Democratic Sen. Bob Menendez of New Jersey, contended Wednesday that any future administration still has authority to go after ISIS and other Iranian backed groups through the still-viable 2001 AUMF that Congress approved for the war in Afghanistan and to go after al-Qaeda - the perpetrators of the Sept. 11 terrorist attacks, as well as to pursue the Taliban, ISIS, and affiliated terror groups.
"This will have no impact on defending against any Iranian threat. The president already has the authority under the '01 AUMF and the constitution for military operations against ISIS or Iranian backed groups that threaten US personnel," Menendez said Wednesday.
The second GOP-sponsored amendment would have repealed that 2001 use-of-force authorization but was roundly rejected by all committee members but its sponsor, Sen. Rand Paul, R-Ky.
The Biden administration said back in 2021 when the House first voted to repeal the 2002 authorization that it supported the effort.
"The administration supports the repeal of the 2002 AUMF, as the United States has no ongoing military activities that rely solely on the 2002 AUMF as a domestic legal basis, and repeal of the 2002 AUMF would likely have minimal impact on current military operations," the administration said in a statement of administration policy.
The repeal effort's fate in the now GOP-controlled House, though, is unclear, despite its sponsors spanning the political spectrum from the far right via Chip Roy of Texas to moderate Democratic Rep. Abigail Spanberger of Virginia.
One senator, a veteran of the Iraq War herself, made a passionate case for repeal Wednesday.
"The documents set the legal framework for military action that are supposed to define the mission for the Americans who are going downrange, but lately, too many in these halls of power in Washington have shrugged off that duty, hiding behind this outrageously outdated document. They've been scared of the political risks that come with bringing these wars back into the spotlight. They've been staring down election days," said double amputee Sen. Tammy Duckworth, D-Ill.
"Congress has shirked responsibility to our troops. For more than 20 years since passing these AUMF's those in power have stretched and skewed their original intent. They've left our troops without a clearly defined mission," she said.
ABC News' Allison Pecorin and Justin Gomez contributed to this report.