WASHINGTON — As President Joe Biden rattled off policy proposals in this year’s State of the Union address, he hit an emotional note when talking about veterans who suffer from cancer after serving on military bases where toxic smoke billowed from burning trash.

“One of those soldiers was my son Maj. Beau Biden,” he said.

The president was careful to avoid drawing a direct line between the burn pits and his son’s fatal cancer, but he left no doubt that he believes there’s a connection. The tragic death from seven years ago makes a ceremony Wednesday, when Biden plans to sign legislation expanding federal health care for veterans, among the most personal moments for him since taking office.

Sen. Jon Tester, D-Mont., who chairs the Senate Committee on Veterans’ Affairs, said Biden was a driving force behind the measure, which passed last week.

“He was continually pushing because whether Beau died of this or not, I think Joe thinks that it had some impact, and so he wanted this fixed,” Tester said. “And because he thinks it was the right thing to do. So different president, different set of priorities, this would have probably never happened.”

Burn pits were used in Iraq and Afghanistan to dispose of chemicals, cans, tires, plastics, medical equipment and human waste. However, 70% of disability claims involving exposure to the pits were denied by the Department of Veterans Affairs.

The legislation will direct officials to assume that certain respiratory illnesses and cancers were related to burn pit exposure, helping veterans get disability payments without having to prove the illness was the result of their service.

“Veterans who have been sickened to the point of being unable to work, unable to take care of their families, won’t have to spend that time fighting the government to get the healthcare they earned,” said Jeremy Butler, head of the Iraq and Afghanistan Veterans of America. “This is monumental.”

Butler is expected to attend the ceremony, along with Le Roy and Rosie Torres, husband and wife advocates for veterans health care who started the organization Burn Pits 360. Le Roy developed constrictive bronchitis after serving in Iraq, making breathing difficult.

Biden will be introduced by Danielle and Brielle Robinson, the wife and daughter of Sgt. 1st Class Heath Robinson, who died of cancer two years ago. The legislation is named for Heath, and Danielle attended Biden’s State of the Union address as a guest of first lady Jill Biden.

Although the provision involving burn pits has garnered the most attention, other health care services will be expanded as well.

Veterans who have served since the Sept. 11 attacks will have a decade to sign up for VA health care, double the current five years.

And there’s more help for veterans from the Vietnam War. The legislation adds hypertension to list of ailments that are presumed to be caused by exposure to Agent Orange, a herbicide used by the U.S. military to clear vegetation.

In addition, veterans who served during the war in Thailand, Cambodia, Laos, Guam, American Samoa and Johnston Atoll will also be considered to have been exposed to the chemical.

The legislation is considered to be the largest expansion of veterans health care in more than three decades, but it became an unlikely political football shortly before it passed.

On the day that the Senate was expected to grant it final approval, Republicans unexpectedly blocked it. Veterans who had traveled to Washington for a moment of triumph were devastated.

“All the veterans were down there because they were expecting to celebrate,” Butler said. “And then they were absolutely stabbed in the back.”

Republicans said they were concerned about technical changes to how the legislation was funded. Democrats accused them of throwing a fit because they were unhappy about a separate deal to advance Biden’s domestic agenda on climate change, taxes and prescription drugs.

Instead of going home, some veterans began holding what they called a “fire watch” outside the Capitol, an impromptu vigil to keep public pressure on the Senate.

They stayed around the clock, despite the stifling summer heat and torrential thunderstorms. Jon Stewart, the comedian who has advocated for veterans, joined them as well. Biden wanted to go but couldn’t because he was isolating with a coronavirus infection, so he spoke to the demonstrators in a video call when VA Secretary Denis McDonough dropped off pizza.

Days after the demonstration began, the Senate held another vote, and the measure passed with overwhelming bipartisan support.

Veterans were in the gallery watching the vote take place.

“Every single person I was with was bawling. Just bawling,” said Matt Zeller, a former Army captain who was among the demonstrators. “I cried for a solid five minutes.”