WASHINGTON, D.C. — Many families of 9/11 victims are furious at President Barack Obama for saying he will veto a bill that would allow them to sue Saudi Arabia for its alleged role in the terrorist attacks.

At a protest in front of the White House on Tuesday, they vented their anger not only against the president, but also against Sens. Lindsey Graham, R-S.C., and Bob Corker, R-Tenn., for trying to stall the legislation, which has already cleared Congress with broad bipartisan support.

The two Republicans have said they are seeking changes that would make it more difficult for the U.S. to be sued in retaliation. The revisions also would make it harder for 9/11 families to file lawsuit, however.

Graham was an original co-sponsor of the bill. Even though he expressed similar reservations in the spring, even briefly placing a hold on the legislation, many supporters blame the aggressive lobbying of the Saudi government for his and Corker’s position.

“I don’t believe them one bit,” said Sylvia Carver, 58, of Maryland, who lost her sister Sharon in the attack on the Pentagon on Sept. 11, 2001.

“Lindsey Graham was one of the first signers, and I think he’s allowing himself to be influenced by the Saudi government. … All of a sudden he’s been wavering,” she said. “So I’m just hoping he and the president stand strong with the American people and not with the Saudi government.”

Carrying photos of victims and signs saying “Stop protecting terrorism” and “Pass JASTA now,” protesters chanted, “Stand with us” and “President Obama, you can’t hide, we’ll get Congress to override.”

The Justice Against Sponsors of Terrorism Act prevents countries accused of terrorism on U.S. soil from claiming sovereign immunity from lawsuits. The White House opposes it because it could open the door to other countries retaliating against American citizens. Supporters of the bill expect Congress to override the presidential veto — for the first time in Obama’s presidency.

“Obama is showing he’s on the side of the Saudis instead of the 9/11 families and the American people,” said Sean Passananti, 47, who carried a photo of his father, who was killed at New York’s World Trade Center. “And (Graham and Corker) had both signed off on it, and now it looks like the Saudis got to them trying to delay the bill. … So we’re going up against big Saudi lobbyists.”

Several protesters cited a report last week by The New York Times that said Saudi Foreign Minister Adel al Jubeir had spoken with Graham to express his concerns and make it clear the legislation would be considered “a hostile act.”

Graham has said he just wants to make sure that “anything we do doesn’t come back to bite us” and that the legislation could be turned against the U.S. later.

After the House of Representatives passed the measure earlier this month, he said it would make sense to buy more time and find a compromise with the president and the bill’s sponsors, in order to advance it without harming the U.S. relationship with a key ally.

Despite his reservations, Graham expects the current bill to become law.

“If nothing changes, President Obama’s veto will be overridden,” his spokesman, Kevin Bishop, said Tuesday.

But 9/11 families who have pushed for similar legislation for over a decade are not buying the diplomatic reasoning, calling it an excuse.

“It’s money. At the end of the day it’s money, and money shouldn’t motivate justice,” said Francine Gallagher, 48, who lost her husband in the World Trade Center, leaving her with an 8-week-old son. “It’s very frustrating because it feels like (Obama) is letting us down, and it breaks my heart that the president of the United States would allow this to happen.”

Eddie Bracken, 49, who lost his sister Lucy in the twin towers, said Obama and Graham are putting “politics before people.”

“After 15 years the memories are still raw, because we didn’t get no justice, and our own government is undermining us,” he said. “(Obama) ain’t doing right by us. My family’s mad, upset and hurt that our president of the United States of America is not helping us.”

The Obama administration has made the same argument as Graham, expressing concerns that the bill could lead to a slew of international lawsuits and have a major impact on relations with a key ally.