Some centrist Senate Democrats are poised to demand restrictions on U.S. security assistance to Israel, as rising death tolls and famine conditions for Palestinians have eroded support among Americans for how the Jewish state has conducted military operations in the nearly six-month war in Gaza.

Frustration has been steadily growing among Democrats about the tactics that the far-right government of Israeli Prime Minister Benjamin Netanyahu has used in its war against Hamas, particularly an intense air bombardment over the densely populated Gaza Strip and the restricting of practically all aid deliveries by land.

In early February, nearly 20 Senate Democrats, led by Sen. Chris Van Hollen of Maryland, were ready to back an amendment to a national security emergency spending bill that would require all offensive weapons paid for by the measure to comply with U.S. law, international humanitarian law, and the law of armed conflict.

The Biden administration issued an executive branch memorandum backing that policy, part of a last-minute compromise that staved off a floor fight at the time that could highlight a rift between Israel and one of the two major political parties of its most important foreign ally, weapons supplier and diplomatic protector.

The situation on the ground in Gaza has grown much worse for Palestinian civilians in the nearly two months since that Senate vote on the national security supplemental.

While it remains unclear what will happen to the Senate-passed supplemental in the House, Democrats in both chambers could seek to revisit the provisions related to funding for Israel in light of the worsening humanitarian situation in Gaza.

If House Speaker Mike Johnson, R-La., decides to bring the measure up under suspension of the rules, there might be enough votes to clear the bill without reopening for changes to the Israel and Palestinian-related provisions.

The Senate-passed version totaling $95.3 billion includes $5.2 billion for Israeli missile defense systems and $4.4 billion in transfer authority to replace U.S. weapons provided to Israel in its war against Hamas as well as $9.2 billion in refugee and humanitarian assistance for the Palestinians and other vulnerable populations.

“Kids in Gaza are now dying from the deliberate withholding of food,” Van Hollen said in a Senate floor speech last month. “That is a war crime. It is a textbook war crime. That makes those who orchestrate it war criminals. So now the question is, what will the United States do?”

And with Netanyahu still planning to launch a full-scale invasion of Rafah, which has 1.2 million people, many of them internally displaced from the war, more centrist national security Democrats such as Sen. Chris Coons of Delaware have said they would support placing restrictions on future aid if Israel does not take steps to reduce civilian casualties and distribute aid.

“It is urgent, and it has been urgent that we deliver humanitarian aid at scale to Gaza,” Coons, who is seen as close to the White House on foreign policy, said in an interview in late March. “While I recognize Israel’s right to defend itself from Hamas, they have to conduct themselves in a way that facilitates the delivery of humanitarian aid at scale.”

In December, a group of six House Democrats who are military veterans of the post-Sept. 11 wars or worked at the CIA released a letter to Biden criticizing Israel’s military strategy for producing such a high civilian death toll and urged the administration “to use all our leverage” to convince Israel to change its operational tactics. That includes Rep. Elissa Slotkin of Michigan, who is running for her state’s open Senate seat in November.

Hannah Morris, director of government affairs for the liberal pro-Israel lobby group J Street, said that “if a Rafah ground invasion proceeds without a clear and credible plan that is implemented to protect civilian life, there will be very real outrage in the Democratic caucus of both chambers.”

“Already, we’ve seen myriad statements, letters referring to the unacceptable loss of civilian life that’s coming from the Democratic caucus and it’s not just progressives,” Morris said. “This is very much a moral and strategic concern that centrist Democrats have.”

Other centrist and establishment Democrats, such as Senate Armed Services Chairman Jack Reed of Rhode Island and Senate Foreign Relations Chairman Benjamin L. Cardin of Maryland, recently have stepped up their criticisms of Netanyahu.

They supported Senate Majority Leader Charles E. Schumer of New York in his calls for elections in Israel in the hopes that new leadership will be elected that would pursue a different policy toward the Palestinians.

Over the weekend, thousands of Israelis took to the streets in the largest protests against Netanyahu’s government since the Oct. 7 mass terrorist attacks, and his far-right coalition government is once again seen as vulnerable to collapse.

Shifting political tides

The pro-Israel advocacy space is keenly aware that its Democratic support base is shifting in the Senate. Several staunchly pro-Israel senators are retiring, such as Cardin and Joe Manchin III of West Virginia; another Israel ally, Bob Menendez of New Jersey, who faces multiple federal corruption indictments, is not running for reelection as a Democrat but says he may launch an independent bid.

House Appropriations Committee ranking member Rosa DeLauro, D-Conn., has also been outspoken about wanting to protect funding to the United Nations refugee agency that provides aid to Palestinians amid concerted GOP and Israeli efforts to end its international financial support.

Sen. Christopher S. Murphy, D-Conn., who heads the Foreign Relations Middle East subcommittee and is a foreign aid appropriator, said his message to Israeli leaders is not that their relationship with the Democratic Party is at stake if they don’t start allowing massive quantities of food into Gaza to mitigate the imminent famine there. Rather, it’s that there will be consequences for Israel’s alliance structure all over the world if widespread civilian death due to starvation occurs.

“I don’t particularly view this moment through a partisan lens. I know that’s a very popular way to think about it here,” Murphy said last month. “I’m thinking about the thousands of children who are going to starve. I don’t really care about the impacts on Israel’s relationship with political parties in the United States. I care about whether we are going to end up with tens of thousands of dead children in the next 60 days.”

A potential invasion of Rafah area of Gaza would add to this. Unidentified U.S. officials have also told news outlets that an Israeli military invasion of Rafah, which President Joe Biden has said is his “red line,” would likely result in a loss of U.S. diplomatic cover for Israel in the United Nations and restrictions for the first time on how Israel can use weapons that it receives from the U.S. in Gaza.

Senior U.S. and Israeli senior officials met Monday over Rafah and had a “constructive engagement,” with the two sides agreeing “that they share the objective to see Hamas defeated in Rafah,” the White House said in a statement. The U.S. side expressed concerns with various courses of action in Rafah, and the Israeli side agreed to take these concerns into account, the White House said.

Netanyahu canceled an earlier planned meeting in retaliation for the U.S. last week abstaining from using its veto on a binding but unenforceable U.N. Security Council resolution that demands an immediate ceasefire in Gaza during Ramadan.

Support for Israel’s war against Hamas has fallen across all three main U.S. political groups but it is the biggest among Democrats, according to a Gallup poll released last week. Seventy five percent of Democrats now oppose the war, compared to 60 percent of independents while just 30 percent of Republicans disapprove. Overall, 55 percent of Americans disapprove of Israel’s actions in Gaza.

The Democratic base has long been to the left of the party establishment when it comes to pushing for greater focus on Palestinian human rights in the long-running conflict with Israel.

Changes in U.S. public support for Israel have traditionally been slow to trickle up to Capitol Hill where ironclad bipartisan support for Israel and the billions of dollars in annual weapons assistance that American taxpayers provide has been treated as sacrosanct in every appropriations cycle.

The Israel-Hamas war has taken what was once a divide between the grassroots and Democratic elected officials and turned it into a chasm, say longtime watchers of the U.S.-Israel relationship.

It used to be that Democrats feared publicly criticizing Israel’s treatment of the Palestinians for fear of being seen as unelectable in the U.S. but now that thinking is shifting in the opposite direction, Phyllis Bennis, program director of New Internationalism at the Institute for Policy Studies, a progressive think-tank, said during an Arab Center virtual panel last week on the impacts of the Israel-Hamas war on U.S. elections.

“This is a movement that is now at the center of political debate within the progressive movement . . . and within mainstream political debate opinion and mainstream media,” she said.

John T. Bennett contributed to this report.