When President Barack Obama climbs the House rostrum tonight, he will face a Democratic Congress shaken to its core by the threatened collapse of its health care reform drive and the growing possibility of a midterm bloodbath.The stakes could hardly be higher. Democratic lawmakers still shocked by the loss of the late Sen. Edward Kennedy’s (D-Mass.) seat last week are looking for inspired direction from their party’s leader.Many have no clue about how to revive their fortunes — or are at odds over the party’s direction. Broadly, the president has a tall order uniting the wings of the Democratic Party, given a fundamental split between liberals who want him to recommit to a strongly progressive agenda and moderate and vulnerable Members who want a pared-down agenda intended to appeal to the middle.Job One for Obama: dragging his signature health care overhaul from the brink of a legislative abyss. Democratic leaders have made no discernible progress forging a new path for the bill after their Bay State defeat ended the party’s Senate supermajority and scrambled what had seemed only days earlier a near-certainty.Instead, they have fumbled around with a menu of options that range from bad to worse — a complex and lengthy fix through budget rules; pared-back measures that accomplish only a narrow slice of what Obama originally proposed; House passage of the now-politically toxic Senate version; or doing nothing at all.Short of advocating a specific legislative route, which Obama is not expected to do, Democrats are looking for their persuader in chief to give the beleaguered reform effort a much-needed boost of public support by remaking the case for its necessity.“I think he has to acknowledge the well has been poisoned and the debate has been lost,— said Rep. Jason Altmire (D-Pa.), a key moderate. “Health care is part of the problem with the economy. … That’s the connection he has to make.—Which will bring the president to Job Two: simply, jobs.About the only thing that Democrats do agree on is that they want the president to talk more about them. But they differ on what exactly that means.Even before the speech, Obama’s proposal for a domestic spending freeze underscored the divisions, with moderates praising the idea as a good first step toward tackling record deficits while liberals argued such an idea was premature and unbalanced at a time when millions are out of work and while Obama is also asking for tens of billions more to fight the war in Afghanistan.In addition to liberal angst over Obama’s pitch for fiscal responsibility, the left wing of the party has also been mounting an effort to revive the public insurance option. They were asking Obama to recommit to it in his speech as a way to fire up the party’s base and strike a populist tone.“It’s time for us to move ahead and do our jobs and provide something to this country to show that the Democratic Party is actually worth electing,— said Rep. Alan Grayson (D-Fla.) at a press conference dropping off petitions for the public option. “We have to deliver. We can’t let people around this country think that the only choices between the political parties are the crazies and the lazies.—That, charitably, is less than likely. And Obama has to placate other key party constituencies with important backers in Congress — including the gay and Hispanic communities, both agitated by a lack of progress on long-held priorities — without promising too much action in an already harrowing election season.