Key Senate Republicans are divided over a GOP senator's bill that would allow families of Sept. 11 victims to sue the government of Saudi Arabia.

In a political twist, Democrats firmly back the legislation even though it puts them at odds with the White House.

President Barack Obama is visiting Saudi Arabia amid the kingdom's threats to pull billions of dollars from the U.S. economy if Texas Sen. John Cornyn's bill is enacted. The legislation from Cornyn, the No. 2 Senate Republican, has sparked a veto threat from the White House, which believes the bill could expose Americans overseas to legal risks.

The unease among Republicans over Cornyn's bill mirrors that of an administration they are frequently at odds with on foreign policy issues.

Separately, the Supreme Court on Wednesday cleared the way for families of victims of the 1983 Marine barracks bombing in Beirut and other attacks linked to Iran to collect nearly $2 billion in frozen Iranian funds. The court's 6-2 ruling directly affects more than 1,300 relatives of victims of such attacks, including several who have been seeking compensation for more than 30 years. The Beirut bombing killed 241 U.S. service members.

The debate over Cornyn's bill underscores the challenges of providing the victims' families with closure and compensation nearly 15 years after al-Qaida extremists hijacked four airplanes and killed thousands of people on U.S. soil Sept. 11, 2001.

The Justice Against Sponsors of Terrorism Act, which Cornyn introduced in September with Sen. Chuck Schumer, D-N.Y., gives victims' families the right to sue the government of Saudi Arabia in U.S. court for any role that elements of the Saudi government may have played in the attacks.

"We should use every means available to prevent the funding of terrorism, and the victims of terrorism in our country should be able to seek justice from people who do fund that terrorist attack," Cornyn said this week.

More than a dozen relatives of Sept. 11 victims have called on Obama to back the legislation and declassify and release U.S. intelligence that allegedly discusses possible Saudi involvement in the attacks.

But Sen. Lindsey Graham, R-S.C., said Wednesday that Cornyn's bill could lead to unintended consequences that stem from U.S. support for the alphabet soup of rebel groups in Syria battling the Islamic State and President Bashar Assad's forces.

Sen. John McCain, R-Ariz., the chairman of the Armed Services Committee, fears that the legislation, if passed, would alienate Saudi Arabia and undermine a longstanding yet strained relationship with a critical U.S. ally in the Middle East.

The chairman of the Senate Intelligence Committee, North Carolina Republican Richard Burr, said he's opposed to Cornyn's bill but declined to explain why. Sen. Bob Corker, R-Tenn., the chairman of the Senate Foreign Relations Committee, remains undecided.

"The bill, I don't think, is yet in its final form," Corker said. "It matters to me what it says."

Graham, the chairman of the Senate subcommittee that controls foreign aid, has said he'll block the bill from moving to the Senate floor until changes are made to ensure the legislation doesn't backfire on the United States. His apprehension is rooted in the potential for a foreign country to sue the United States if the door is opened for U.S. citizens to take the Saudis to court.

For example, Graham cited the Kurdish People's Protection Units, or YPG, which the U.S. backs and has been called the most effective force in fighting the Islamic State group in northern and eastern Syria. The YPG is related to the Kurdistan Workers' Party, or PKK, a group that Turkey and its allies have labeled a terrorist organization. If the YPG were to collaborate with the PKK on a terrorist attack inside Turkey, Graham asked, would the U.S. be liable?

"Imagine this bill applied to your own country," Graham said. "I want to know it works."

Sen. Jeff Sessions, R-Ala., initially had problems with the bill but said Wednesday his objections had been resolved and he had no intention "of trying to stop people from being able to sue for damages that they ... have a right to sue for."

Sessions, a former federal prosecutor and Alabama attorney general, appeared exasperated when asked about revisions he supported that may have expanded the scope of the bill.

"It was obvious to me from Day One (that) this is a delicate issue legally and you gotta be really careful with it," he said. "We talked with the State Department. We made recommendations that got accepted. And then there was no more complaints, I understood, at the time."

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