For President Barack Obama, solving the Congressional health care puzzle after Wednesday night’s speech could come down to a question of “Who do you trust?—

Can you trust Sen. Chuck Grassley (Iowa), the ornery lead Republican negotiator in the Finance Committee who waxes poetic about bipartisanship even as he sends out fundraising letters vowing to defeat “Obamacare—?

Or Finance Chairman Max Baucus (D-Mont.), who always seems to have a new, later timeline for getting a bipartisan bill done?

Or Rep. Mike Ross (D-Ark.), the lead Blue Dog negotiator on health care who brokered a deal for a public insurance option in the Energy and Commerce Committee before the August recess only to vow the morning after Labor Day to vote against any such bill?

Can Obama trust House liberals’ threats to kill any bill without a “robust public option,— or would enough of them go along with a “trigger— if Obama and Speaker Nancy Pelosi (D-Calif.) give their blessing?

Or can Senate Majority Leader Harry Reid (D-Nev.) deliver on a partisan reconciliation bill if Baucus’ bill falls apart?

Part of the problem, of course, is that absent sharp lines in the sand from the White House, some Members have been repositioning themselves as sentiment on health care reform has shifted in their districts.

That’s what happened in Ross’ case. The head of the Blue Dog health care task force said in an interview Wednesday that the overwhelming majority of people in his 37 town halls and the more than 90 appearances he made at events back home opposed a public option.

“Those are the people I’m here to represent,— Ross said.

That said, even Ross left at least some wiggle room for a deal that would include a trigger — an idea he and other Blue Dogs floated months ago.

“I would have to see what a trigger looked like, who pulled it, and when,— Ross said. He noted that the trigger was actually a Republican idea, incorporated in the 2003 Medicare bill.

One political advantage of the trigger idea is that the concept is so squishy that it can be stretched to mean anything. Can the White House sell House liberals on the idea that a strong trigger equals a “robust public option—? And can they do so without scaring off conservative Democrats in both chambers, including Members like Ross who have vowed to oppose a public insurance option?

For everyone who is willing to consider a trigger, there are other Members vowing to kill it.

“Trigger’ is another way of saying kill the public option,’— said Rep. Anthony Weiner (D-N.Y.), who complained the public insurance option in the House bill is already “so weak and so watered down I would have a hard time voting for it.—

Ross dismissed the deal he cut before the break. “I don’t think any of it matters,— he said. In the end, he predicted, “90 percent of [what ultimately gets voted on] is going to be the Senate Finance bill.—

Congressional Progressive Caucus Co-Chairwoman Lynn Woolsey (D-Calif.) has been trying to shoot down any trigger trial proposals, including those coming from the White House. “The insurance companies had 50 years,— she said. “We need to pull that trigger now.—

House leaders face another problem — a conflict between a desire to carry a strong bill into conference with the Senate in order to have something left to compromise, and the desire of rank-and-file conservative Democrats not to vote for a liberal bill that stands no chance of becoming law.

“A lot of our Members from tough districts voted for the cap-and-trade bill that’s either going to go nowhere or come back looking a lot different,— Ross said. “I think it’s unfair to ask them to do that again.—

Complicating the House math, another senior Democrat noted that the converse isn’t true: Vulnerable Members who did not vote for the climate change bill don’t feel compelled to support the health care overhaul.

House Democratic leaders and the three committee chairmen responsible for the bill are already busy reaching out to caucus groups to gauge support and identify problem spots, with a goal of pulling together a bill by the end of next week. The leadership huddled Wednesday with freshmen, sophomores and members of the New Democrat Coalition and the Progressive Caucus. They are set to meet today with the Blue Dogs and members of the Tri-Caucus.

Tory Newmyer contributed to this report.