Nancy Pelosi is confronting a conundrum on trade as she walks a delicate line between the president she champions and the caucus she leads.

The House minority leader is among President Obama’s strongest backers on Capitol Hill, but liberals in her caucus — still resentful of the North American Free Trade Agreement (NAFTA) they say failed to meet its promise of helping U.S. workers — are lining up in opposition to Obama’s call for fast-track trade authority.

Fast-track would pave the way to the Trans-Pacific Partnership (TPP) with 11 other nations, which is a central part of Obama’s “pivot” to Asia.

{mosads}Pelosi (D-Calif.) has said repeatedly that she’s seeking “a path to yes” on the sweeping trade deal, but the full-throated opposition from liberals puts her in a tough spot.

Pelosi, along with her entire leadership team, has remained uncommitted on the fast-track legislation, adopting Obama’s advice that Democrats hold their critiques in the early stages of the debate. Publicly, she says she’s still reviewing the bill.

“If you say ‘no’ from the get-go, then you can’t improve the product,” said a Democratic aide familiar with Pelosi’s behind-the-scenes message to Democrats.

Fast-track legislation, unveiled last week by Sens. Orrin Hatch (R-Utah) and Ron Wyden (D-Ore.), and Rep. Paul Ryan (R-Wis.), is poised to move through committees in both chambers this week.

If approved, it would prevent Congress from amending the TPP, making it much easier for Obama to seal the deal. It could also help the White House complete a separate trade pact with the European Union.

Top Democrats, including Reps. Chris Van Hollen (Md.), senior Democrat on the Budget Committee, and Sandy Levin (Mich.), the ranking member of the Ways and Means panel, are already sounding warnings that the bill doesn’t go nearly far enough to address their TPP concerns, particularly on issues related to currency manipulation and the protection of U.S. workers. 

“On all of the major issues in the negotiations, the negotiating objectives are obsolete or woefully inadequate,” Levin said.

Pelosi has not been one to shy away from trade fights in the past. Indeed, she helped lead a successful charge against granting President Clinton fast-track authority in 1998, and she voted against a similar measure under President George W. Bush in 2002.

Her record on actual trade pacts is more mixed. Pelosi voted in favor of NAFTA in 1993, and backed deals with South Korea and Panama in 2011. But, joining most House Democrats, she also opposed a Colombia trade agreement pushed by Obama in 2011.

Looking ahead to the TPP, Pelosi said earlier this year her decision would hinge on one variable: “The impact on the paychecks of America’s workers is the standard that we will use.”

A second House Democratic aide, speaking anonymously to discuss strategy, predicted Pelosi would ultimately vote against the fast-track bill this year — but quietly, so as not to weaken Obama’s hand. 

“She wants to help Obama in any way she can, but she’s not going to support it,” the aide said Monday. “[But] she’s not going to lead a whipping effort against this thing — no way.”

The Democratic division has not been overlooked by Republicans. The office of Speaker John Boehner (R-Ohio) released a statement Monday highlighting the discord and asking why Obama has been forced “to convince his fellow Democrats to put politics aside and do the right thing for American jobs.”

Still, a number of Republicans — who have long accused Obama of abusing his executive power — are balking at the notion of granting the president broad new authority in negotiating trade. The Republicans’ own infighting means GOP leaders might need Democratic support to secure enough votes to pass the fast-track legislation — a dynamic that makes Pelosi’s position that much more crucial.

Ed Gerwin, a trade expert with the Progressive Policy Institute, a centrist Democratic group that supports the fast-track bill, said Pelosi’s reticence is bolstering Obama’s hand.

“Whether or not she ends up as a supporter, what she has been doing is very helpful in trying to get to yes, on trade,” Gerwin said. “What Pelosi has been doing, combined with the significant efforts by Wyden in the Senate, may allow Democrats to put more of a stamp on trade and may help some members keep an open mind on TPA and eventual trade deals.”

The results of Pelosi’s strategy will be known soon enough. The Senate Finance Committee, led by Hatch and Wyden, is holding a Tuesday hearing on the fast-track bill, with a markup scheduled for Wednesday. And the House Ways and Means panel, led by Ryan and Levin, could follow as soon as Thursday. A floor vote in the House is possible as soon as next week, with the Senate expected to follow in May.

Heading into those votes, the stakes for Obama and TPP supporters couldn’t be higher, as the failure of the fast-track bill could sink the transpacific deal it’s meant to catalyze. It’s a dynamic that GOP leaders, who have struggled in counting votes on a number of bills this year, are well aware of as they seek support for the fast-track bill.

“It’s a humongous risk to take if they feel like they might not have the votes,” the second Democratic aide said. “I don’t think they get a second go-round on this.”

Vicki Needham contributed.

This story was updated at 3:07 p.m.