Lashed by liberals and threatened with more government regulation, the insurance industry nevertheless rallied its lobbying and grass-roots resources so successfully in the early stages of the healthcare overhaul deliberations that it is poised to reap a financial windfall.

The half-dozen leading overhaul proposals circulating in Congress would require all citizens to have health insurance, which would guarantee insurers tens of millions of new customers -- many of whom would get government subsidies to help pay the companies' premiums.

"It's a bonanza," said Robert Laszewski, a health insurance executive for 20 years who now tracks reform legislation as president of the consulting firm Health Policy and Strategy Associates Inc.

Some insurance company leaders continue to profess concern about the unpredictable course of President Obama's massive healthcare initiative, and they vigorously oppose elements of his agenda. But Laszewski said the industry's reaction to early negotiations boiled down to a single word: "Hallelujah!"

One of the Democratic proposals that most concerns insurers is the creation of a "public option" insurance plan. The industry launched a campaign on Capitol Hill against it, grounded in a study published by the Lewin Group, a health policy consulting firm that is owned by UnitedHealth Group. The lobbyists contended that a government-run plan, which would have favorable tax and regulatory treatment, would undermine private insurers.

Opposition increased this month when boisterous critics mobilized at town hall meetings held by members of Congress home for the August recess.

The attacks, supplemented by conservative critics on talk radio and other forums, drew national attention.

Leading insurers, including UnitedHealth, urged their employees around the country to speak out. Company "advocacy hot line" operations and sample letters and statements were made available to an army of insurance industry employees in nearly every congressional district.

Some insurers supplemented the effort with local advertising, often designed to put pressure on specific members of Congress. Late in the spring, Blue Cross Blue Shield of North Carolina -- the home state of several conservative Blue Dog Democrats -- prepared ads attacking the public option.

Leading Democrats have fought back, with House Speaker Nancy Pelosi (D-San Francisco) last month calling the industry "immoral" for its past treatment of customers and suggesting insurers were "the villains" in the healthcare debate.

Still, recent support for the public option has declined, and the stock prices of health insurance firms have been rising.