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Here's why the TPP is such a big deal
03:24 - Source: CNN
Washington CNN  — 

President Barack Obama is promising his personal support to fellow Democrats who end up supporting a proposed Pacific trade deal that is controversial to many of his supporters.

In a nearly hour-and-a-half long meeting on Thursday, Obama addressed concerns and answered every question from 25 members of the New Democrat Coalition, a group of moderate members of his party, according to a congressional staffer.

“He acknowledged it’s a hard vote and he made it clear that if any of them needed and wanted him to campaign for them, he would support them on the campaign trail,” the staffer said.

Some Democrats fear there could be a primary challenge if they support the trade proposal.

RELATED: 6 reasons why the Trans-Pacific Partnership matters

“I’ve got your back,” Obama told the room, according to Rep. Gerald E. Connolly, D-Virginia, the vice chairman of the New Democrat Coalition.

Although the House Democrats left the meeting feeling positive, the staffer added, “Whether one meeting with the President is enough to sway these guys is unclear. It was definitely a positive step by the President and the administration.”

Obama’s push for free trade was boosted last month when key House and Senate committees passed legislation setting up trade promotion authority, allowing deals negotiated by the administration to get a vote in Congress without any amendments.

But as the measure heads to the House floor for a vote, which could come this month, it continues to face fierce opposition from the vast majority of House Democrats.

The top House Democrat, Rep. Nancy Pelosi, D-California, sidestepped efforts to take a position on the bill. Instead, she said she was working to ensure any trade bill protected jobs in the U.S.

RELATED: Obama needs Clinton on trade, Boehner says

“Is what is being put forth better than the status quo? In some cases, yes. In some cases, no,” she said on Thursday. “But … weighing all of those equities, what does it come down to for increasing the paycheck of American workers?”

House Speaker John Boehner predicted the legislation would ultimately be approved, but said Thursday, “This bill is always a heavy lift.”

The President, meanwhile, voiced frustration a few weeks ago that some fellow Democrats were disparaging his trade agenda.

“When people say these trade deals are bad for working families, they don’t know what they’re talking about,” Obama said at an event hosted by Organizing for America, the political group that advocates for his agenda. “I take that personally.”

The President said his entire record reflected boosting working families – and lambasted fellow Democrats who he characterized as grabbing onto his populist coattails.

“I’ve been talking about reversing income inequality and social mobility since before it was cool,” he said. “I’ve got a bunch of people now talking about inequality. But back then they sure weren’t.”

“Back then people were saying I was preaching class warfare,” he added. “Now, suddenly, it’s their campaign platforms.”

Trade promotion authority has been handed at points to every president since Richard Nixon. Bill Clinton used it to pass the North American Free Trade Agreement, and deals with South Korea, Colombia and Panama were green-lighted early in Obama’s presidency under authority that had been originally given to George W. Bush.

The Trans-Pacific Partnership is the first deal that could advance under the authority, since negotiators have said they’re close to finalizing the pact, which includes all of North America, Australia, Japan – which is the real pearl of the deal in U.S. businesses’ eyes – and a handful of other Asia-Pacific countries.

But another one, which would smooth out regulatory differences in areas like vehicle safety rules and chemical inspections between the United States and the European Union, could follow it.

CNN’s Eric Bradner contributed to this report.