In a coup for House Democrats, AARP will endorse sweeping health care overhaul legislation headed for a history-making floor vote, officials told The Associated Press on Wednesday.

An endorsement from the seniors' lobby was critical when then-President George W. Bush pushed the Medicare prescription drug benefit through a closely divided Congress in 2003. House Democratic leaders are hoping it will work the same political magic for them as they strive to deliver on President Barack Obama's signature issue.

An announcement from the 40-million member group is expected Thursday, said officials with knowledge of the group's decision. They spoke on condition of anonymity because the endorsement is not official yet.

Backing the 10-year, $1.2 trillion House bill is a tricky move for AARP. Many retirees are concerned about cuts in Medicare payments to medical providers, which will be used to finance an expansion of health insurance coverage to millions of working families who now lack it. Also, AARP says its membership is about evenly divided among Democrats, Republicans and independents, meaning its endorsement in today's highly politicized atmosphere could anger many members.

Floor votes on the House bill could come as early as this weekend. Obama planned to visit the Capitol on Friday, according to congressional officials. They spoke on condition of anonymity because the meetings have not been announced.

Meanwhile, the Congressional Budget Office released an analysis of the House GOP bill that found it would reduce the number of uninsured by just 3 million in 2019. By comparison, the more expansive Democratic bill would gain coverage for 36 million.

While the Democrats' bill would cover 96 percent of eligible Americans, the Republican alternative would cover 83 percent _ roughly comparable to current levels. The budget office said the Republican plan would reduce federal deficits by $68 billion over the 10 year period and push down premiums for privately insured people.

House Democratic leaders moved on Wednesday to shore up support for the measure among their rank-and-file, even as they sharpened their fight with the health insurance industry.

Asked Wednesday if Democratic leaders had the 218 votes needed for passage, House Majority Leader Steny Hoyer, D-Md., responded: "We're counting. We're counting."

Last-minute changes to the Democrats' bill cleared the way for votes as early as Saturday.

In a move aimed directly at health insurance companies, the revised House bill would launch a federal-state crackdown on what it terms "unjustified premium increases." Insurers have sought above all to block creation of a government insurance plan, which happens to be the top legislative goal for liberals.

Under the bill, insurance companies would have to publicly disclose the justification for premium increases before they go into effect. The federal Health and Human Services department would monitor patterns of premium increases, and could take action if the price hikes are out of line. The bill would also provide $1 billion to state insurance commissioners, allowing them to ramp up their own enforcement.

Democrats also strengthened a provision that would strip the industry of its decades-old exemption from federal antitrust laws.

Supporters said the tougher approach is needed to keep insurance companies from artificially boosting premiums in advance of the major reforms taking effect in 2013.

Other late changes to the bill, such as enhanced status for the government's office of minority health, were intended as sweeteners for supportive lawmakers, including members of the Congressional Black Caucus. Continued...