The bill would have added five new casinos as well as slot machines at horse-racing tracks.
Supporters have promised to try to override a veto by the governor.
The governor said he vetoed the gambling bill because it lacked ethical standards and regulatory oversight.
The question going in Tuesday was would the governor veto the entire bill, or would he use his amendatory veto power to re-work the bill to his liking. The governor opted for the former saying the gaming expansion plan was deficient in many ways. At the same time, he said he stands ready to work with all parties in crafting a "better bill." Some of those parties are doubtful of that.
"It takes less time to do a thing right than it does to explain why you did it wrong," he said.
The governor quoted Longfellow to students at Longfellow school in Oak Park, but his message was clearly meant for supporters of the gambling bill - a bill that the governor thinks is so flawed, he had to veto it.
"We're not going to have loopholes for mobsters in Illinois," Quinn said. "It's woefully deficient for protecting honesty and integrity in the regulation of gambling in our state."
The governor said the main failing of the bill is that it does not call for a ban on campaign contributions to politicians from gaming interests, and further, that it doesn't direct a high enough share of gaming profits to education.
"I spent all summer trying to reach the governor," said State Rep. Lou Lang (D-Skokie).
The chief sponsor of the gaming bill, Lang said he repeatedly offered to add a provision that would ban campaign money from gaming interests, but the governor never responded.
"This bill is clean. It's well written, and the simple fact is that this governor doesn't want to sign the bill," he said.
Lang said the votes will be there to override the governor's veto. Senate Republican leaders disagree.
"I think there's enough wrong with the bill to start over," said Sen. Christine Radagno, (R) Il. Sen. GOP leader.
In the past, the governor has said he was fully opposed to placing slot machines at the state's horseracing tracks - which is part of the vetoed bill. But his language today suggests he could consider that as part of a re-worked gaming expansion plan.
"In the veto message, he didn't address slots at racetracks so we're comfortable that's an old issue and we can move on and get this issue passed," said Tim Carey, president, Hawthorne Race Track.
"I look forward to working with then legislature and people outside the legislature and the mayor of Chicago in getting a better bill," said Quinn.
The governor did call Chicago's mayor Tuesday morning and told him he was going to veto the bill which included a long-sought casino for the city. In a written statement, Mayor Rahm Emanuel says that he will work relentlessly to pass a gaming bill that will bring a casino to Chicago and that he and the governor agreed that "it cannot take another 20 years of discussion to draft and pass a bill that will be signed into law."
First will come the veto challenge.
The bill is SB1849. Online: www.ilga.gov.
