’Tis the season for compassion, mythology, and hardball politics. Which makes next week, after Thanksgiving and before Christmas, the perfect time for the lame-duck U.S. Senate to be deciding the fate of a bill that would pay the medical costs for thousands of people suffering from illnesses caused by the September 11 terrorist attacks. Win or lose, though, the city has reason to be proud of its politicians, who’ve fought through scientific uncertainty and Republican shamelessness to bring the bill this far.

A week after the Twin Towers fell, then-EPA boss Christine Whitman declared the downtown air safe; whether she was merely wrong or whether Whitman was lying to help speed the reopening of the stock market, ground zero recovery workers and neighborhood residents were sadly misled. Mayor Rudy Giuliani proclaimed that the enormous dust cloud and raging fires produced asbestos levels that “are either safe or nonexistent.” Yet subsequent studies, particularly by the FDNY’s Dr. David Prezant, have shown the presence of significant levels of pulverized glass, cement, insulation fibers, asbestos, and a stew of toxic chemicals.

One of the rescue workers who inhaled the nasty mix was James Zadroga, an NYPD detective. Zadroga had been on his way home from work when he heard that the World Trade Center had been struck by planes; he drove downtown and patrolled the site for weeks. Several months later Zadroga got sick; in January 2006, at the age of 34, he died. Exactly why Zadroga’s lungs failed has been fiercely disputed ever since. At least three doctors attributed the damage to breathing toxic ground zero air; the city’s medical examiner said Zadroga had injected himself with ground-up prescription pills that clogged his lungs.

Even if Zadroga is a flawed hero, he’s long been a potent political symbol: Gov. George Pataki signed the first James Zadroga Act, granting additional benefits to the families of city workers who died of 9/11-related illnesses, back in August 2006. In the past decade Mt. Sinai has documented WTC-related disabilities, but fortunately New York’s politicians didn’t wait for the lab results, recognizing that much of the medical fallout, especially respiratory problems, would surface slowly. Hillary Clinton, as senator, pushed early for emergency funding. In the House, Carolyn Maloney and Jerry Nadler assembled the James Zadroga Health and Compensation Act, a bill that would end the need for yearly battles over patchwork appropriations to cover the care for World Trade Center workers and neighbors. “This bill had to be negotiated with the city, the unions, the contractors, and there were a lot of different questions,” Nadler says. “How much should the survivors get? How much responsibility should the city have? The negotiations went on for years, mostly behind the scenes, and they were very tough.”

Marshalling votes for what’s now a $7 billion program became especially treacherous as the 2010 midterms approached. In July, congressional Republicans threatened to attach an amendment barring undocumented immigrants from receiving WTC health payments; Democrats feared they were being trapped into a vote that could be used against them in attack ads, provoking Anthony Weiner’s infamous rant on the House floor, in which he screamed that the Republicans were “cowardly” for hiding behind procedure instead of voting against the bill because they thought it was a bad idea. Then, on September 29, came a more dramatic, if quieter, moment: With the bill finally on the floor, an upstate Republican congressman introduced a surprise, last-minute 70-page amendment. Nadler and Maloney huddled with House staffers, frantically trying to sort through all the extraneous provisions while keeping the “yes” votes in line and reassuring Speaker Nancy Pelosi she didn’t need to pull the bill; with key help from Long Island Republican congressman Peter King, the Zadroga bill passed decisively.

The Senate is proving to be a much closer call. Kirsten Gillibrand, who diligently took up the cause when she replaced Clinton, traveled to Pakistan and Afghanistan two weeks ago and spent much of the time lobbying John McCain, Joe Lieberman, and Lindsay Graham to vote in favor of the bill. Mayor Michael Bloomberg, who was bluntly skeptical that Zadroga’s death was related to WTC dust, visited Washington last week and secured a pledge from Illinois’s Mark Kirk, making him the first Republican senator in favor — and leaving the bill one vote short. The chief remaining objection? The “pay-for,” in Beltway lingo. Democrats want to fund the bill by closing corporate tax loopholes; Republican opponents are calling that a tax increase. Maloney and Nadler, the bill’s two most dogged advocates, continue to make calls and cross their fingers. If the Zadroga bill doesn’t pass now, it won’t survive next year’s Republican takeover of the House. “This health care should have been considered part of the war on terror from the beginning,” Nadler says. “Nobody who isn’t crazy — like the New York Post — denies the medical evidence anymore. I’m fairly optimistic we’ll have a happy ending. But it’s the last few minutes of a game that won’t go into overtime.”