WASHINGTON (CN) – The Senate voted 54-46 Wednesday to end America’s involvement in the Saudi-led war in Yemen, potentially setting the stage for President Donald Trump to use veto powers for the first time.

Newly recruited Shiite fighters, known as Houthis, mobilize to fight pro-government forces in Sanaa, Yemen. (AP Photo/Hani Mohammed, File)

The resolution to end American aid in a war that has been largely invisible to most U.S. taxpayers places the president in a tense political situation.

The measure serves as a direct challenge by lawmakers to Trump’s history of exhibiting greater leniency towards Saudi Arabia despite the kingdom’s role in the war in Yemen, the growing civilian death toll there, the displacement of 3 million people, the deaths of 85,000 children and a famine which has touched some 14 million.

The Trump administration’s response to the brutal murder of Washington Post journalist Jamal Khashoggi at a Saudi consulate in Turkey last year also exacerbated criticism that the president places too much importance on America’s strategic alliance with the Saudis while failing to establish a clear position of moral or ethical authority.

This is the second time the resolution has come before the Senate.

It passed 56-41 in the Senate in December but then-Speaker of the House Paul Ryan, a Republican, refused to take it up. Current Speaker of the House Nancy Pelosi, a Democrat, picked the resolution back up in January once the new Congress was sworn in.

Though the House ultimately passed the resolution in February, an inadvertent procedural issue stopped it from being sent to a full vote in the Senate.

Wednesday’s “do-over” vote was necessary, according to Senator Bob Menendez, D-N.J.

“The longer the conflict goes on, the larger Iran’s foothold in Yemen grows and the more entrenched opposing political factions become. We’ve heard reports that U.S. coalition partners may be transferring U.S.-origin weapons to known terrorist organization,” Menendez said.

He added, “The reports of abuse and torture are alarming and it is in the interest of the United States to put as much political pressure on the parties to end this conflict as we can.”

The bill, which invokes the War Powers Resolution of 1973, is sponsored by a bipartisan group of lawmakers, including Independent Vermont Senator Bernie Sanders, Republican Senator Mike Lee of Utah and Democratic Senator Christopher Murphy of Connecticut.

Ahead of the vote, Sanders said the resolution was a “major step forward” to ending the war and alleviating the suffering of people – some of the poorest in the world – caught up in the fighting.

The resolution also gives important powers back to Congress, he said.

“As every school child should know, Article 1 of the Constitution clearly states that it is Congress, not the president, that has the power to declare war… but over many years, Congress has abdicated that responsibility to Democratic presidents and Republican presidents alike. Today we begin the process of reclaiming our constitutional authority by ending U.S. involvement in a war that has not been authorized by Congress and is clearly unconstitutional,” Sanders said.

The stakes are so high now, the bill’s sponsors mutually agreed, because the civil war spurred by Saudi Crown Prince Mohammad bin Salman has killed thousands and caused the most severe famine in nearly 100 years, according to a recent United Nations report.

“The fact is, the U.S., with little media attention, has been Saudi Arabia’s partner in this horrific war. We have been providing the bombs the Saudi-led coalition is using. We’ve been refueling their planes and assisting with intelligence,” Sanders said.

But several Republican lawmakers, like Dan Sullivan of Alaska and James Inhofe of Oklahoma, decried that premise.

Ahead of the vote, Inhofe said he opposed the resolution because if implemented, it would “end all security cooperation with our partners in Yemen against the Houthis,” an Islamic religious sect with a history of anti-America sentiment.

“We’re not engaged in hostilities in Yemen against the Houthis. We are providing intelligent support that helps construct a strike list which protects humanitarian aid workers. If we pull support, Israel loses, Iran wins and the humanitarian situation worsens,” Inhofe said.

Sullivan, who also opposed Wednesday’s resolution, said the bill would interfere with U.S. ability to provide humanitarian aid.

In the last 14 months, the U.S. has dedicated $697 million to aid and the Saudi’s have invested over $1 billion, he said.

But Sullivan said Iran, “the country that started this war,” hasn’t spent a dime.

The resolution’s Republican sponsor, Senator Lee, rebuffed Sullivan’s assertion.

“This resolution doesn’t say anything about ending humanitarian aid. It says we shouldn’t be in a war half a world away that doesn’t involve us,” Lee said. “If someone wants to implement a resolution to start a war in Iran, then let’s have that discussion. But this is separate.”

Iran’s support of Houthi forces is “far less significant than the administration claims,” Sanders added.

“The fact is the relationship between Iran and the Houthis has only been strengthened by this war. This war is creating the very problem the administration claims it wants to solve,” Sanders said.

A December report by the Middle East Institute appears to corroborate Sanders’ claim.

It quoted Iranian Foreign Minister Mohammad Javad Zarif as saying he would personally support an end to the conflict in Yemen if terms proposed by former Secretary of State John Kerry in 2016 were put into play by the new administration.

The Kerry terms required the Yemeni president to step down in exchange for a Houthi military withdrawal but the proposal was ultimately rejected by the Saudi-backed Yemeni government.

Tehran also expressed public support for peace talks on Twitter last year, inviting “all sides to enter constructive and responsible engagement to end the crisis in Yemen.”

After the vote Wednesday, the White House could not immediately be reached for comment. But if last year’s position by the White House is any indication, a veto by the president seems all but certain.

When the resolution was first considered, the White House balked, saying it would “negatively impact the ability of the United States to prevent the spread of violent extremist organizations.”

Though it received enough votes in the Senate on Wednesday, members of Congress must still band together to overturn a presidential veto.

If they don’t overturn the veto, the U.S. could remain involved in the Yemen conflict indefinitely.