Much of the American left is critical of Israel, particularly since its incursion into Gaza. But in the halls of Congress, even progressive Democrats beloved by grassroots activists are loath to criticize the Jewish State’s ongoing military offensive.

A Pew Research Center poll released Monday showed that a plurality of Democrats across the country, 35 percent, and liberals, 44 percent, said that Israel had “gone too far” in its response to its conflict with Hamas. Meanwhile 47 percent of Democrats told Gallup that Israel’s actions during the current conflict were “unjustified,” compared to just 31 percent who thought the opposite.

But these opinions are nearly impossible to find in Congress. Democrats, when asked a question about Israeli operations in Gaza, had two standard responses: irritation, or else a statement of their broad support of Israel, without going into specifics. It was as if the very mention of Israel turned the question into a hostile interview.

“Look, man, I’m a politician, with multiple constituencies. Why should I alienate one just so that you can write a story?” Democratic Rep. Keith Ellison angrily told The Daily Beast. Ellison, a stalwart progressive, was the first Muslim-American elected to Congress.

Ellison cited a Tuesday op-ed he had written that was critical of the Gaza blockade, but became noticeably agitated when asked to expand on his views. In particular, he did not want to address whether Israel had gone too far during its current operations in the Gaza Strip.

Sen. Bernie Sanders, a darling of the left who identifies as a democratic socialist, was curt. His tone changed suddenly when the topic shifted from the Veterans Administration bill that he had been shepherding through Congress to Israel’s operation in Gaza.

“That’s not where my mind is right now,” he told the Beast.

Democratic Rep. Sandy Levin said he was on his way to a meeting and didn’t have time to discuss the issue. (He did, however, stop for another reporter, who asked about transportation funding.) When Rep. Krysten Sinema, a Democrat from Arizona, was approached, she simply repeated that she supports the right of Israel to defend itself.

There has been essentially no congressional criticism of Israel’s actions in Gaza. Two weeks ago, after Israel announced it had begun Operation Protective Edge, the Senate unanimously passed a resolution expressing its support for Israel’s right to defend its citizens, and called on Hamas to immediately cease attacks against Israel.

“Coming to the defense of Israel is not a partisan issue—it is an American principle,” said House Majority Leader Harry Reid, making the case for lawmakers to approve hundreds of millions in spending for Israel’s Iron Dome defensive system.

Lawmakers are largely supportive of the Pentagon’s request for $225 million in Iron Dome funding, although the Senate wants to include it as part of a broader border crisis bill, while the House wants to vote on its separately. Nevertheless, should Iron Dome funding come up for a vote this week, it is expected to receive overwhelming support.

Pro-Israel progressives say the Democratic base’s objections to Israel’s operation in Gaza stem from the high death toll among civilians.

“Any time there are civilians dying, children dying, progressives are upset, as they should be. In general, we have more sympathy for the deaths of civilians than our friends on the right. They’re much more pro-war,” a Democratic congressional aide said.

And as Ellison’s frank comments suggest, lawmakers have to worry about alienating Jewish constituents before November’s midterm elections. For example, a recently leaked memo from Georgia Democratic Senate candidate Michelle Nunn’s campaign was explicit in tying a pro-Israel message to support from Jewish voters and fundraisers.

“If you just keep your mouth shut, it’s hard to imagine progressives abandoning you,” one progressive pro-Israel activist said. “There isn’t a lot of upside and potentially a lot of downside of a lawmaker getting on the wrong side of a community that is riled up, especially in the run-up to an election…intensity beats numbers, and the people who support Israel are very intense.”

For the left, congressional support for Israel is such a given that many have turned to other methods to influence the debate.

“[Activists] look at Congress as hopeless. Moving Congress or moving the administration is hopeless,” said Kevin Martin, executive director of Peace Action, an anti-war group. “That’s why there’s a shift to [the BDS movement] rather than…trying to influence congressional or administrative policy on Israel.”