WASHINGTON -- Former president Bill Clinton predicted Tuesday that President Barack Obama's signature health overhaul will become law even as fellow Democrats in the US Congress hunted for critical, elusive votes.

"I just want it to pass, and I think it will," he told reporters during a rare visit to the US Capitol for closed-door talks with Senate Democrats, billed as focused on climate change and job creation.

As enough Democrats wavered to put the fate of the historic legislation's in doubt, Clinton stressed "it doesn't have to be perfect" and predicted lawmakers would have to keep working to fine-tune the system.

"It takes a long time to get these things done," said the former president, who told reporters he would be "one happy fella" when the legislation passed but that his wife, Secretary of State Hillary Clinton, might be even happier.

"Maybe Hillary'll be the happiest person in America, I'll be the second happiest person. Even more than President Obama, even more than (White House chief of staff) Rahm (Emanuel)" and other top aides, he said.

During his administration, Hillary Clinton took the lead in crafting a sweeping health care overhaul, only to watch it crumble in 1994 under attacks from Republicans and insurers and doubts from centrist Democrats.