– The pain of Sept. 11, 2001, never goes away for Gina Cayne.

When she speaks of losing her husband as he worked on the 104th floor of the World Trade Center's north tower, tears well in her eyes, her voice strains.

"They killed my husband," she said, accusing Saudi officials of financing the attacks that claimed thousands of lives on that day. "All I want is my day in court."

She might be within weeks of getting it.

For more than 14 years, relatives of the nearly 3,000 people who died that Sept. 11 battled Washington and several federal judges for the right to sue Saudi Arabia and the royal family in Riyadh — suspected by families and senior members of Congress of providing money and other support to the 19 attackers.

First, district and appellate courts in New York ruled — repeatedly — that a legal protection called "sovereign immunity" prevented the families from suing Saudi Arabia. Then President George W. Bush and President Barack Obama stymied one effort after another by Congress to pass a bill that would open a path for a case to proceed.

But the families' fortunes changed in September, when during a distracting, raucous 2016 presidential campaign, Congress delivered the only veto override of Obama's tenure and made the Justice Against Sponsors of Terrorism Act, or JASTA, law.

It has already had an effect: While JASTA was being debated, a federal judge in New York ordered Iran to pay the families and insurance companies $14 billion for having allowed some of the hijackers to enter and leave the country before Sept. 11 without having transit visas stamped in their passports. Such visas would have made it more difficult for them to enter the United States.

Now, the families are heading to court in the coming weeks, seeking a punitive payout that legal experts say could exceed $1 trillion.

But Saudi Arabia is not done fighting — in court or in Congress. Indeed, Riyadh looks ready to pump unprecedented sums into a lobbying effort to unwind the new law.

The Saudis have hired a team of Washington power brokers who have held senior White House and congressional posts going back decades, paying 17 firms in Washington, Houston, Cleveland, Denver and Alexandria, Va., more than $1 million a month to try to turn back the clock.

This time, though, the families can boast of an advantage they've never had before — a president who supports their right to sue. President Donald Trump, a native New Yorker, vowed on the campaign trail to do everything he could to help the families, and those families believe he will stand by them even if Saudi money succeeds in turning Congress against a law it just passed.

"There's no question Trump would veto that," said Bill Doyle, a retired Wall Street stockbroker who lost his son. "He lived only 30 blocks from ground zero. He was down there constantly after the attacks."

Less than a year after the attacks, families filed suit in the U.S. Southern District Court of New York in lower Manhattan. The lawsuit accused almost 150 people, companies and organizations across the Middle East and beyond as having helped carry out the attacks.

One group of defendants was obvious: Osama bin Laden, Taliban chief Mullah Omar and Khalid Sheikh Mohammed, the Pakistani-born head of Al-Qaida propaganda and self-professed plotter of the attacks. He would be captured in 2003 and is being held with other alleged terrorists at the U.S. military prison in Guantanamo Bay, Cuba.

But the families didn't stop there. Their suit accused officials and government agencies in Iraq, Afghanistan and Saudi Arabia as well as Muslim banks, relief groups, youth leagues and charitable organizations around the globe and even groups in Washington state, Minnesota, Massachusetts and elsewhere in the U.S.

Named too were some of the most prominent Saudis.

The legal brief zeroed in: "Prince Sultan bin Abdulaziz al Saud, the Saudi defense minister, and Prince Nayeff bin Abdulaziz al Saud, the Saudi minister of the interior, have provided hundreds of millions of dollars to Bin Laden and Al-Qaida," it said. (Prince Nayeff bin Abdulaziz al Saud is now crown prince, making him heir to the Saudi throne.) "That funding enabled Bin Laden to pursue his terror agenda."

Over the next dozen years, before several suits were consolidated into one, federal judges would rule that it was the president, not the courts, who held authority to designate a foreign country as a terrorist supporter. The Saudi government, the judges decided, had "sovereign immunity" from lawsuits under long-standing U.S. law.

Most families accepted payments — $2.1 million on average — from a compensation fund created by Congress. In exchange, they gave up their right to sue the U.S. government, U.S. airlines or other companies, while retaining the power to file suit against "knowing participants in the hijacking conspiracy."

But 70 families refused to accept payments. Some felt the money was too little, too late; others didn't want to limit their legal rights.

Gina Cayne was one of the 70. To her, the payments were hush money. She wanted a judge or a jury to determine who is guilty of having murdered her husband.

Bill Doyle is one of the de facto leaders of the families group pushing to sue. He lost his 25-year-old son, Joseph Doyle, on Sept. 11.

The younger Doyle was working for Cantor Fitzgerald on the 101st floor when American Airlines Flight 11 struck it between the 93rd and 99th floors. Doyle was not able to call his parents to say goodbye. "I did get a driver's license and a credit card," his father said quietly. "That's the only part of my son I have."

Bill Doyle threw himself into making the tragedy's perpetrators pay for their crime. He contacted lawyers and lawmakers, made frequent trips to Washington and devoured everything he could read about the attacks.

Doyle has become a one-man information clearinghouse. He painstakingly assembled a database with all the contact information and details of loss, later sharing it with the government.

Like others, Doyle concluded that it was impossible for the hijackers — with few independent means, low education and limited English — to have acted alone. And so he focused on the men that he became certain were the hijackers' sponsors: senior Saudi officials and members of the royal family.

Over the next decade, Doyle worked with lawmakers and attorneys to craft legislation that would let families sue the Saudi government.

According to Doyle, he and the families' lawyers had frequent contact with Bush and Obama administration officials in the State and Justice Departments, addressing their concerns over a bill that would eventually be called the Justice Against Sponsors of Terrorism Act.

But that wasn't his only angle. He wanted the federal government to release the 28-page Saudi section of the intelligence committees' 2003 report on the attack's causes.

So on Sept. 11, 2011, when Obama traveled to ground zero to mark the 10th anniversary of the attack, Doyle was there. At a private lunch afterward, he confronted Obama. "He got up and he said to me, 'I will get them released,' " Doyle recalled. "And I said, 'Oh, God bless, thank you.' For five years, nothing happened."

Doyle has a more visceral goal: He wants to see Prince Bandar punished.

While serving as Saudi ambassador to the United States, Bandar became one of the capital's most prominent diplomats. Now crown prince and retired in Saudi Arabia, he was head of its intelligence apparatus from 2012 to 2014.

The 28 pages suggest that money from Bandar was funneled to two of the Saudi hijackers through an intermediary suspected of being an intelligence agent for Riyadh.

The federal court rulings that shielded Saudi Arabia sparked a bitter battle on Capitol Hill and at the White House to change the law granting sovereign immunity to foreign governments.

The then-chairman of the Senate Intelligence Committee, Florida Democrat Bob Graham, was at the center of it.

Soon after the attacks, Graham began to see raw intelligence suggesting that the Saudi hijackers had not acted alone. He learned that before the attacks, some of them had met with senior Saudi officials in the kingdom and in California, where several had lived.

Graham would later learn of a wealthy Saudi family in his home state that had befriended other of the hijackers in Florida, and then fled their Sarasota home just weeks before the attacks.

Graham helped lead the first congressional investigation of the attacks, co-authoring a report based on 500 interviews that said communication breakdowns within and among the FBI, the CIA and other federal and local intelligence and law-enforcement agencies had contributed to the failure to uncover the plot.

But when the House-Senate Joint Inquiry report was released after a seven-month review by U.S. intelligence agencies, its authors noticed an omission; the final 28-page chapter, examining possible Saudi ties to attacks.

That redaction bothered Graham so much that for the next 13 years, while still in Congress and then after he retired in January 2005, he made it his mission to get the missing pages released. The U.S. government released the long-withheld congressional intelligence chapter on possible Saudi ties on July 26, 2016. Although partly redacted, the 28 pages revealed hints but no proof of official Saudi involvement in the terror attacks.

Focusing on three hijackers who had lived in Southern California, the section revealed their interaction with two possible Saudi intelligence agents and their friendship in San Diego with a Saudi man, Osama Basnan.

After the attacks, Basnan told an FBI undercover agent that he had helped the hijackers, was an avid supporter of Bin Laden and had cashed a $15,000 check from an account belonging to Bandar.

Both the Saudi government and the Obama administration said the secret section showed, as the then-White House press secretary Josh Earnest put it, "no evidence that the Saudi government or senior Saudi individuals funded Al-Qaida."

Graham disagreed, and still does. "It points a strong finger at Saudi Arabia's involvement," he said.