There are more than 72,000 people enrolled in the program and 33,000 in treatment, including nearly 8,500 being monitored or treated outside the New York metropolitan area. More than 200 police officers and firefighters who worked at Ground Zero have died from 9/11-related illnesses, officials say. That tally now includes Marci Simms, an NYPD lieutenant who died last week from lung cancer that had been treated under the federal health program. She was 51 and had toiled at Ground Zero for four months during her first year as a cop.

The original law is named for James Zadroga, an NYPD officer who in 2006 became the first to die of respiratory disease linked to Ground Zero toxins. And it was hard enough for the New York delegation to get it through Congress in 2010. It took years of medical studies to establish a link between the respiratory illnesses that first responders were reporting and the weeks that they spent digging through the rubble of the Twin Towers. And only after an extended public shaming by Jon Stewart on “The Daily Show” did Democratic leaders push through the Zadroga Act over opposition from Republicans who worried about its cost. Five years later and with Republicans now in control of Congress, the push to extend and make it permanent is that much heavier a lift. “Let’s face it: The overwhelming majority of Republicans voted against it the first time,” said Representative Peter King, a Republican from the New York suburbs in Long Island.

With the raw emotions and the brief period of post-9/11 national unity having long since faded, King and his colleagues have had to fight the perception that the World Trade Center Health Program is a parochial concern. They cite the thousands of patients who live outside the Northeast, and the fact that the program is open to survivors of the simultaneous attack at the Pentagon and the crash of Flight 93 in Pennsylvania.

But the Congress of 2015 is not the Congress that locked arms and sang “God Bless America” on the Capitol steps in 2001—more than three-quarters of those serving in the House and Senate now were not in office on 9/11. “Much of that is diminished,” King said. “It’s like ancient history, like the Battle of the Bulge or Pearl Harbor.” He told me it’s not uncommon for him to run into first responders he had met years ago who are now carrying around oxygen tanks. Maloney told me something similar, recalling that she had kept in touch with survivors who were fine for years after the attacks. “Now they’re telling me they’re sick, they have six months to live,” she said. When Stewart returned to Capitol Hill to lobby for the legislation in mid-September, he told reporters that what most disturbed him was how many lawmakers treated the issue like “just another bill.”

While senior Republicans in the House have proposed a five-year extension for the program, supporters are pushing to make it permanent for two main reasons. The first is simply that officials expect survivors to develop illnesses related to 9/11 for many more years. The second is that they are dreading the possibility that they will have to bring sick first responders back down to Washington in another five years to lobby for more funds, at a time when the political potency of 9/11 will have diminished even further.