House Democrats returned to Capitol Hill on Tuesday after a brutal August recess to begin the difficult work of stitching together a consensus on health care reform.

And while Democratic leaders searched for unity in advance of a pivotal Wednesday address to Congress by President Barack Obama, deep cracks in the Caucus were barely beneath the surface.

Divisions started at the top, with Speaker Nancy Pelosi (D-Calif.) once again declaring a public insurance option “essential— to the success of a broader package hours after her No. 2, House Majority Leader Steny Hoyer (D-Md.), suggested it might need to be cut loose to garner enough votes to pass the chamber.

Pelosi also appeared to open the door a crack to a “trigger— that would use the public insurance option only as a fallback if private insurance companies fail to hold down costs and improve quality.

But Pelosi warned the insurance industry that if a trigger is included, it would be tied to an even stronger public insurance option down the road.

“They’d be better getting a public option now than one that is triggered because if you have a triggered public option, it’s because the insurance industry has demonstrated that they’re not cooperating, they’re not doing the right thing, and I think they’ll have a tougher public option to deal with,— Pelosi said after a meeting at the White House with Obama and Senate Majority Leader Harry Reid (D-Nev.).

Majority Whip James Clyburn (S.C.), the No. 3 Democratic leader, had signaled earlier Tuesday that a trigger might be necessary. “There are ways to get a public option,— he told MSNBC on Tuesday morning. “I do believe we can have a health care reform bill that includes a public option that is acceptable to people who don’t want a public option.—

Despite the apparent fissures, House Democratic leaders made a show of unity after an early evening huddle Tuesday, claiming broad consensus on the need for reform and 85 percent on the substance. “There’s no division,— Pelosi said. “We all support a public option.—

Pelosi has been working hard to keep a public insurance option alive — opposition is strong in the Senate and the White House has been waffling on the issue — but faces a tough job convincing conservative Democrats bruised by weeks of angry town hall meetings.

[IMGCAP(1)]Her job got tougher Tuesday morning when the chairman of the Blue Dog Coalition health task force, Rep. Mike Ross (D-Ark.), announced he would oppose any bill that contains a public insurance option, citing overwhelming opposition from his constituents. Ross had been the lead negotiator behind a breakthrough deal before the August break that included a public option in the Energy and Commerce Committee markup, but that agreement now appears to be in tatters.

A House leadership aide sought to minimize the Ross defection and said the deal was simply a way to get the bill out of committee. Liberals had already vowed to vote against any measure that included the deal, arguing that the public insurance option that survived would be too weak because it wouldn’t be tied to Medicare and that too many cuts were made to health care subsidies for the uninsured to cut costs.

And while some like Ross were abandoning ship on the right, four liberal House Democrats — Reps. Mike Capuano (Mass.), Sam Farr (Calif.), Bill Pascrell (N.J.) and Jim McGovern (Mass.) — were weathering a backlash among left-wing activists after they told Roll Call that they would be open to a trigger approach.

“Any Democrat contemplating a trigger is contemplating letting some of their constituents die each of the next five years in order to prove a point we already know: Private insurance companies are bad-faith actors that profit by denying care and need competition now,— said Adam Green, co-founder of the Progressive Change Campaign Committee. “Any Democrat who votes for a trigger should prepare for a primary challenge.— His group is collecting petition signatures from Obama’s 2008 campaign supporters to pressure him into backing a strong public insurance option.

But the fiscally conservative Blue Dog Democrats have been pushing such a trigger for months, and the idea has been considered by the White House as one with the potential to break the logjam on health care in the Senate.

The trigger concept has been backed by Sen. Olympia Snowe (Maine), the only Republican in either chamber to voice support in any form for a public insurance option.

Rep. Debbie Wasserman Schultz (D-Fla.), who heads the Democratic Congressional Campaign Committee’s “Frontline— program to retain vulnerable Members, said Tuesday that she supports a strong public insurance option but also did not rule out using a trigger as a compromise to get a bill done.

“We need to get as much significant health care reform to the president’s desk that we can,— she said on a conference call with reporters.

Meanwhile, despite a heated August, Wasserman Schultz said vulnerable rank-and-file House Democrats remain committed to passing health care reform.

“I haven’t talked to a single Frontline member who is wavering in their support for health care reform — on the contrary,— she said.