Reporting from Washington — As the House prepares to convene this afternoon for action on President Obama's long-pursued overhaul of healthcare, the House's Democratic leadership is voicing confidence in passage of the bill.

"We've got the votes,'' said Rep. John Larson (D-Conn.) in an appearance this morning on CNN's State of the Union.

"This is a historic day, and we are happy warriors,'' Larson said. "We will be a part of history, joining Franklin Delano Roosevelt's passage of Social Security, Lyndon Johnson's passage of Medicare and now Barack Obama's passage of healthcare.''

Rep. Mike Pence, an Indiana Republican also appearing on the CNN program, was asked about the GOP's strategy going forward.

"I don't know if they have the votes,'' said Pence. "We are going to use every means at our disposal to oppose this government takeover of healthcare… I believe this is going to be a historic weekend, but I believe it's going to be different than John thinks it will be.''

The House plans to convene at 1 p.m. EDT to take up a "reconciliation" measure that merges the House and Senate on healthcare and vote on a Senate-passed healthcare bill. House leaders need 216 votes for passage, and the leadership's Larson asserted unequivocally that they will have them.

Republicans, for their part, say that the long-running political play known as healthcare reform will not end on Capitol Hill.

"I don't know if they have the votes today," Pence said, voicing a Republican stance that Democrats will pay for passage of the $940-billion healthcare bill in the midterm elections. "I guarantee you, the American people know they have the votes in November. "

For weeks, Democratic have been cajoling, arguing and reassuring their own members that the current healthcare plan was viable on policy and political levels, though the final version is far different from what the House passed last year -- and even more different from what many liberals in the House originally wanted.

Obama, who postponed a trip to Asia to deal with any last-minute problems, gave more than 50 speeches around the country to push for healthcare changes that he said were more than 100 years overdue and were badly needed now.

"Don't do it for me. Don't do it for the Democratic Party. Do it for the American people. They're the ones looking for action right now," Obama told Democrats on Saturday afternoon.

House Democrats expect to hold three votes Sunday. The first is to accept the formal rule that describes the time and terms of debate. That will be followed by an up-or-down vote on the Senate bill, and then by the package of amendments, House leaders say.

If passed, the Senate bill would go to Obama for his signature and the amendments would go to the Senate, where Democratic leaders say they have the 51 votes needed for passage. If the Senate passes the amendments, that too, goes to Obama for his signature to become law.

In the policy debate, Republicans will likely stress their core arguments: that the bill is too expensive and broadens government powers too much. They will argue that the majority Democrats have rammed the bill through, avoiding GOP policy suggestions.

Democrats accuse the Republicans of refusing to negotiate on the bills in order to hand Obama a major political defeat. Democrats also say they have incorporated some Republican suggestions into the final legislation

Under the legislation, most Americans for the first time would be required to purchase insurance, and they would face penalties if they refused. The bill includes billions of dollars in subsidies and tax breaks to make insurance more affordable, and it also provides for an expansion of Medicaid, the government healthcare program for the poor.

The healthcare legislation would extend coverage to about 32 million uninsured Americans and would impose new rules on insurance companies to prevent them from denying benefits because of preexisting conditions. It would establish insurance exchanges to increase competition among insurance companies.

The healthcare plan would cost $940 billion over 10 years, according to the Congressional Budget Office. It calls for new taxes and fees as well as cuts in Medicare, the insurance program for the elderly.

Democrats argue the cuts would eliminate waste, fraud and abuse, while Republicans charge that the cuts would decrease services for the aged.

noam.levey@latimes.com

michael.muskal@latimes.com