WASHINGTON — Former President Bill Clinton told anxious Senate Democrats on Tuesday to pass a health care bill soon because the U.S. economy can't resist the toxic combination of exorbitant medical costs and nearly 50 million uninsured for much longer.

"My argument was that this is an economic imperative," Clinton said after the closed-door meeting.

Addressing Democrats' insecurities about the complex legislation, Clinton said he told the senators "there is no perfect bill — you'll always have unintended consequences. There will be amendments to this next year. But the worst thing to do is nothing."

Clinton was the last Democratic president to attempt to revamp the health care system to cover all Americans and try to control costs. The spectacular collapse of his plan probably cost Democrats control of Congress in 1994, but Clinton is still admired for having tackled the issue. He went on to win a second term in office.

"People trust him," said Sen. Max Baucus, D-Mont., one of the architects of the current Senate health care bill.

"His argument was that getting the best bill is not only good for the people, it's the best politics," said Sen. Ben Nelson, D-Neb., one of a clutch of moderates who hold the fate of the legislation in their hands.

Clinton said he hoped all the senators understood his bottom line: "It's not important to be perfect here," he said. "It's important to act, to move, to start the ball rolling."

The House passed its health care bill last Saturday by a narrow 220-215 vote. In Senate, Majority Leader Harry Reid, D-Nev., is working on a final Democratic draft. But the combination of divided Democrats, and Republicans determined to force delays under the Senate's arcane rules, is making it less likely that President Barack Obama will get a bill this year.

"Our goal is to make sure it's out of the Senate this year," said Sen. Dick Durbin, D-Ill., the No. 2 Senate Democrat. The Senate bill would then have to be combined with legislation passed Saturday by the House, and the final version passed by both chambers before it could go to Obama's desk. Finishing that whole process before year's end would be tough.

"They want us to finish quickly. We do too. But some of these things are beyond our control," Durbin said of the White House's desire for fast action.

Complicating the effort, abortion opponents in the Senate are seeking tough restrictions in the health care overhaul bill, a move that could roil the shaky Democratic effort.