President Barack Obama answers media questions after an unannounced appearance Feb. 9 at the White House daily press briefing in Washington. Obama has summoned both Democrats and Republicans to a White House summit at Blair House, to be cast live on C-SPAN and perhaps cable Thursday.

Washington ? Coming soon to daytime television: America’s long-running civic drama over how to provide better health care to more of its people without breaking the bank.

President Barack Obama summons anxious Democrats and aloof Republicans to a White House summit Thursday — live on C-SPAN and perhaps cable — and gambles that he can save his embattled health care overhaul by the power of persuasion. Adversaries and allies alike were surprised by Obama’s invitation to reason together at an open forum, as risky as it is unusual.

Ahead of the meeting, the White House will post on its Web site a health care plan that modifies the bill passed by Senate Democrats last year. The modification is an effort to address the concerns of their House counterparts.

The plan is important, but not as critical as the political skill Obama can apply to an impasse that seems close to hopeless in a pivotal congressional election year.

“It’s a high-stakes situation for him more than anybody else,” said Gerald Shea, the top health care adviser for the AFL-CIO. “If the judgment is either that it’s a political farce, or if it fails to move the ball forward significantly … that would be very damaging to the issue and to him.”

A viewers’ guide to the White House meeting, looking at Obama and his plan, Republicans in Congress and divided Democrats:

Obama

He has two main goals. One is to show the American people that the Democrats’ health care plan is reasonable, and much of its complexity reflects the sprawling nature of the insurance system. The other is to argue that lockstep Republican opposition is not reasonable and could spoil a historic opportunity on a problem that concerns all Americans.

“I don’t want to see this meeting turn into political theater, with each side simply reciting talking points and trying to score political points,” the president said Saturday in his radio and Internet address. “What’s being tested here is not just our ability to solve this one problem, but our ability to solve any problem.”

Obama’s main audience will be Democrats, who must overcome their divisions — and ease their qualms — to get a final bill. He will also tune his pitch to independents, who soured on the Democratic bills after initially being open to health care changes.

Thursday’s meeting at Blair House — the presidential guest quarters across from the White House — comes nearly a year after Obama launched his drive to remake health care at an earlier summit he infused with a bipartisan spirit. The president will point out that Republicans have supported individual elements of the Democratic bills.

But his latest plan has little chance of getting GOP support. Built on the Senate bill, it would require most Americans to carry coverage, with federal subsidies to help many afford the premiums. It would bar insurance companies from denying coverage to people with medical problems or charging them more. Regulators would create a competitive marketplace for small businesses and people buying their own coverage. The plan would be paid for with a mix of Medicare cuts and tax increases.

A Democratic source familiar with the details said the White House proposal would scale back the Senate bill’s tax on high-cost insurance plans. It would also strip out special Medicaid deals for certain states, while moving to close the Medicare prescription coverage gap, and making newly available coverage for working families more affordable.

Republicans

GOP leaders in the House and Senate say they cannot accept the Democratic bills, and they want to start over to shape narrower legislation that cuts costs for small businesses and uses federal dollars to set up special insurance pools for people with medical problems.

Obama doesn’t want to stop there.

Republicans want to place limits on medical malpractice judgments, an approach the Congressional Budget Office says would save money by reducing defensive medicine. Obama has toyed with the idea, saying he agrees that something should be done, but thinks limits on jury awards go too far.

Some Republican leaders have questioned whether there’s any reason to go to the summit, but a boycott would play into Obama’s hands. To complicate matters, Democratic liberals have begun an effort to get a government insurance plan back in the bill, a nonstarter for Republicans.

Democrats

Democrats no longer have the 60 votes needed to overcome Republican delaying tactics in the Senate, but they still control both chambers. Yet passing anything but a very modest bill would likely mean using special budget rules that let Democrats override Republicans in the Senate with a simple majority. Using the budget route — called reconciliation — to resolve differences between the House and Senate bills probably would enrage Republicans.

That means Democrats will have to stick their necks out, and some may lose their seats this fall if they support an all-or-nothing push on health care.

Democrats are looking to Obama to give them the confidence they need to get back on track. He did it once before, with his address to Congress last September, after a summer of town hall meetings at which angry grass-roots activists attacked the Democrats on health care.

Democrats “tried to climb a taller mountain than they thought existed,” said former House Speaker Newt Gingrich, architect of the 1994 Republican election victory that followed the collapse of the Clinton health care plan. “They went on a bigger trip than they prepared for.”