– In a rare rebuke, Democratic Sens. Amy Klobuchar and Al Franken plan to override President Obama’s veto of a measure that would allow victims of the Sept. 11 terrorist attacks to sue the government of Saudi Arabia for any role in the plot.

The Wednesday vote is setting up an extraordinary confrontation between Democrats and a president in the final months of his term, a leader to whom Minnesota’s two senators have displayed nearly lockstep allegiance. The major disagreement on foreign policy between Obama and congressional Democrats has led to what could be the first congressional override of a veto during Obama’s presidency.

Franken and Klobuchar were both original sponsors of the measures, called the Justice Against Sponsors of Terrorism Act, that will allow families of the Sept. 11 victims to sue Saudi Arabia directly for any role in the attack.

The measure united Congress at a time of almost paralyzing partisan gridlock, sailing through both chambers earlier in September at the urging of grieving families who say they are seeking justice 15 years after the worst terrorist attack in U.S. history.

Not only did Congress pass the measure easily, members vowed to uphold it against a veto.

“I think it’s a very good way to find out more about exactly what happened and what role the Saudis played in this if they had to go to court,” said Franken, who was also outspoken last week against an arms sale to Saudi Arabia.

In his three-page veto message sent to members of Congress, Obama said the law would hurt U.S. national security interests and upset long-standing international principles of sovereign immunity. Obama said enactment of the law could encourage other countries to exercise the same rules and give foreign courts jurisdiction over the United States and members of its military.

Obama’s arguments

Obama cautioned that the proposed law “does not enhance the safety of Americans from terrorist attacks and undermines core U.S. interests.”

Obama issued the veto without any public ceremony, a move that seemed designed to limit attention over a debate that has pitted him against the families of terrorism victims.

The issue has migrated to the presidential race between Democrat Hillary Clinton and Republican Donald Trump, who both said they would have signed the bill as president.

The Kingdom of Saudi Arabia is against the legislation and has deployed influential lobbyists and advocates on Capitol Hill — including former Minnesota Sen. Norm Coleman — to persuade members to oppose the veto override, pointing out that the 9/11 Commission already exonerated the Saudi Arabian government.

But the commission’s narrow finding did not rule out that less senior officials or parts of the Saudi government played a role in the attacks.

As the political showdown looms, Saudi leaders have said they may sell billions of dollars in American assets if the bill passes to buffer their government against what could be a deluge of legal fees.

Klobuchar said that if the country did nothing wrong, they should have nothing to fear.

The growing political pressure over the measure has underscored the influence of the families of 9/11 victims.

Klobuchar has worked with Beverly and Tom Burnett Sr. of Northfield, whose son died on United Flight 93 when it crashed in a Pennsylvania field on Sept. 11. The Burnetts have been vocal supporters of the legislation. In an editorial on CNN.com, they said they wanted to do something to prevent another 9/11.

“We realized that it was imperative that we take action to hold the people, organizations and foreign nations that helped Al-Qaida accountable for their murderous conduct,” they wrote. “We owed that much to Tom and the others who lost their lives.”

Two-thirds vote required

Klobuchar said she disagreed with the president that the legislation was too broad, saying it’s a relatively small change that could make a big difference for families.

“I think this is narrow enough and important enough that we should override his veto,” she said.

Overturning a presidential veto requires a two-thirds vote in both chambers. Because Republicans have mostly been supportive of the legislation, this was a steeper hurdle in the Senate, where the GOP has a narrower majority. But with so many Democratic defections — including Franken and Klobuchar — the override effort is expected to be successful.

Secretary of Defense Ash Carter sent a letter Monday to some members of Congress saying the bill leaves U.S. military personnel vulnerable to foreign lawsuits.

Franken said he doesn’t believe the law will have that effect because the United States doesn’t commit acts of terror.

“That’s not what we do. There are casualties, civilian casualties, sometimes, when we’re involved in war, when we’re involved with trying to kill terrorists,” Franken said. “There’s a very big difference between ... planning and financing a terrorist attack and civilian casualties in a situation where you are targeting terrorists or enemy soldiers.”