Updated 5:14 p.m.

The trade agreement, known as the Trans Pacific Partnership, has been in the works for nearly a decade and would more closely align the economies of the U.S., Canada, Mexico and nine other countries in South America and Asia. The deal would eliminate tariffs on goods and services and generally harmonize dozens of regulations that can often complicate doing business across borders. (Everything you need to know about the Trans Pacific Partnership, explained by The Post's Lydia DePillis, can be read here.)

The White House is eager to finish the talks with its would-be trading partners and has been pushing to earn the authority to bypass Congress and quickly approve the deal. But most Democratic lawmakers don't want to give Obama "fast track" trade authority to quickly negotiate and approve the deal.

The resistance could complicate things for Obama on two fronts. First, any sign of serious opposition in Washington will make countries involved in the talks nervous that the American president can't seal the deal back home. But second -- and more importantly for The Fix's purposes -- Obama has to balance his desire to get a deal with the political needs of congressional Democrats, dozens of whom run the risk of losing their seats in November.

Already, Senate Majority Leader Harry M. Reid (D-Nev.) and House Minority Leader Nancy Pelosi (D-Calif.) are opposed to moving forward with granting Obama fast-track authority.

"Everyone would be well-advised just to not push this right now," Reid said late last month. He's generally opposed to large global trade agreements.

Pelosi doesn't oppose the concept of fast-track, but said last week that she is against a bipartisan measure introduced by Sens. Max Baucus (D-Mont.), Orrin G. Hatch (R-Utah) and Rep. Dave Camp (R-Mich.) that would give Obama the authority.

Resistance from Reid and Pelosi usually would be enough to at least ease the White House push. But Obama and Vice President Biden have also been directly confronted on the issue in recent weeks by rank-and-file members. But 151 House Democrats co-signed a letter late last year written by Rep. Rosa DeLauro (D-Conn.) to voice opposition to fast track authority and the TPP -- more than half of the caucus. And during a recent closed-door meeting at the White House, Obama took two questions on the subject, while Biden faced a grilling on the subject at the House Democratic policy retreat last week.

At the White House, Obama heard an earful from from Reps. Marcy Kaptur (D-Ohio) and Alan Grayson (D-Fla.), two outspoken liberals with close ties to the labor movement and other liberal constituencies.

Kaptur said she had a simple request for Obama: Let Congress and the public see the details of the TPP before Congress is asked to give him fast track authority.

"He did not say yes," she said in a recent interview. "That means that we would be faced with a fast-track vote that would lock our ability to amend without even knowing what’s in the agreement. I can’t do that. Not when we have $9 trillion of accumulated trade deficit, which is the reason for our budget deficit, because we’re losing middle-class jobs in our country and we’ve outsourced millions of our jobs, a third of our manufacturing base is gone."

Grayson said he wanted to remind Obama that the U.S. faces hundreds of billions of dollars in trade deficits with other countries.

In response, Obama "didn’t give me any sense that, any reason to believe that these free trade agreements that are being negotiated now are going to be any different than the ones we’ve negotiated in the past," Grayson said in a recent interview. "They’ve consistently, and almost to an unbelievable extend, exacerbated our trade problems. I told the president specifically this: That what’s actually happening is that we’re buying goods and services from foreigners and creating jobs in their countries and they are not buying our goods nor our services. What they are doing is buying our assets and driving us deeper and deeper into debt. So we lose twice, we lose because those jobs go overseas and because we go deeper and deeper into debt."

Despite the Democratic opposition, White House Press Secretary Jay Carney said Tuesday that “we’re going to continue to press" for fast-track authority.

But if Obama pushes too hard, he risks upsetting rank-and-file Democrats and key liberal support groups in the labor and environmental communities that always have concerns with major international trade deals. Upsetting those groups might prompt them to sit on their hands or not spend as much money backing Democratic candidates in November.

But if Obama doesn't push hard enough for fast-track, he risks upending an historic trade deal that would help advance his administration's long-sought "pivot" to Asia and upending similar trade talks underway with European countries.

That's why for now, at least, the White House's push for fast-track trade authority has slowed to a crawl on Capitol Hill.