That's because even though the Senate had already approved the measure, the House was deadlocked as it tried to negotiate a deal for one of the sectors most dependent on immigrant labor: agriculture.
Since the bill offered a path to citizenship for many people living illegally in the U.S., growers were concerned that their source of labor, once legalized, would pack up and look for better work. The concern was legitimate: Nearly a third of people who eventually benefited from the amnesty were farm workers, and agricultural work was one of the hardest, lowest-paying jobs around. Growers wanted a guest-worker program that would guarantee them a workforce.
The two main negotiators on the agriculture component in the House were both Democrats from California. Leon Panetta spoke for the growers. He hailed from a district that included the Central Valley, one of the country's most productive agricultural regions. On the other side of the table was Los Angeles-based Rep. Howard Berman, who served as a stand-in for union farmworkers.
Schumer served with Berman on the House judiciary committee, where the bill was being blocked, which is how he became involved. He knew Panetta personally as well as professionally. At the time, they both shared a house in D.C. with two other legislators, a living arrangement the The New York Times described as a nerdy, middle-aged fraternity.
Coming from Brooklyn, Schumer wasn't an expert on agriculture, but he quickly digested the outlines of the negotiations, according to Berman.
"Chuck is very bright. He's a very quick study, so he understood it," said Berman, who lost his reelection bid last fall. "Basically, it was me and my folks with Leon and Leon's folks, with Chuck -- if we were stuck at an impasse -- throwing out some ideas."
Schumer's ties to New York City proved helpful, too. Unions and Latino-rights organizations, whose approval would be vital to any deal, considered him an ally.
"He wasn't coming from a rural state dominated by agricultural interests...From our standpoint, he was well positioned," said Charles Kamasaki, the former executive vice president of the National Council of La Raza, the largest Hispanic advocacy organization in the U.S. and one of the negotiators concerned with Latino rights at the time.
According to Panetta, Schumer also displayed formidable stamina, as evidenced by his frequent trips back to New York, and the ability to bring people together.
"Chuck was a great facilitator in trying to make it happen. It's an example of how you're supposed to get legislation put together in the Congress," said Panetta, who later went on to serve as CIA director and defense secretary. "It's exactly the opposite of what goes on on the Hill these days."
After months of deal-making, the two sides reached an accord on October 17, 1986. The immigration bill would offer a special path to citizenship for agricultural workers, but also provide a guest-worker program meant to guarantee a future supply of farm labor.
Schumer was among many players who made the agreement possible, but he also acknowledged that the country was entering new and unknown territory.
"The bill is a gamble, a riverboat gamble," he told The New York Times. "There is no guarantee that employer sanctions will work or that amnesty will work. We are headed into uncharted waters."