The comedian, who warned first responders they would be exposed to "possibly toxic levels of bull**** and arrogance" from lawmakers this morning, said Wednesday all Americans are indebted to the firefighters, police officers and EMS workers who rushed to the World Trade Center and later worked at Ground Zero.
Stewart has long advocated for sick first responders, and is credited with helping pass the initial legislation in 2010, after bringing four sick first responders on his show to publicly pressure Republican lawmakers filibustering the passage of the bill.
More than 30 Republicans have endorsed the extension proposal, but supporters are looking for more cosponsors, given resistance to funding the programs permanently.
Stewart spent the morning lobbying Senate offices -- even chasing down Nebraska Sen. Deb Fisher, a Republican who has not signed on to the bill, in a Senate hallway.
He pressed a copy of the bill into her hands, before introducing her to a wheelchair-bound first responder with cancer.
“You could be a hero in this,” he said to Fischer, who wasn't in Congress when the health programs were first passed in 2010.
"I don't know anything about the bill," Fischer told ABC shortly after meeting Stewart. "I hadn't heard anything until he chased me down the hall."
Speaking this afternoon after several meetings, he said, "The real test appears to be whether we can carry the momentum from these meetings to actual legislation."
Stewart may not have his old bully pulpit, but he said he knows plenty of people on television.
"If you don't sign on to this type of thing, it has to be known," he said.
McConnell said Wednesday that the Senate will take up re-authorization of 9/11 programs, but did not say whether he supports a permanent extension, as Stewart and the bill's supporters have called for.
ABC's Ali Weinberg contributed to this report.