Emotional disagreements over trade erupted in Congress on Wednesday, when a liberal senator postponed a committee's likely endorsement of a top trade priority for President Barack Obama.

The day began with Senate Finance Committee Chairman Orrin Hatch, R-Utah, predicting a "strong bipartisan vote" for "fast track" legislation. The measure would renew presidential authority to present trade deals that Congress can endorse or reject but not amend.

But liberal Sen. Bernie Sanders, I-Vt., a fierce opponent of the trade legislation, invoked a Senate scheduling rule to postpone the committee's actions for hours. "This job-killing trade deal has been negotiated in secret," said Sanders, who made a lengthy Senate speech denouncing the legislation. "It was drafted with input by special interests and corporate lobbyists, but not from the elected representatives of the American people."

Hatch rejected the claims, saying fast track and other trade proposals have been carefully negotiated and will undergo long public scrutiny.

"We need to be doing all we can tear down barriers to American exports while, at the same time, creating enforceable rules for our trading partners so we can be sure that American workers and job creators are competing on a level playing field," Hatch said.

He said the committee would work late into the night if necessary to address many proposed amendments. "We're going to finish this bill today, I don't care how much time it takes," he said.

The Hatch-Sanders dispute is one of many emerging as Congress turns to trade proposals bitterly opposed by labor unions and others who say trade pacts hurt U.S. jobs.

Obama says his Democratic opponents have their facts wrong. He wants fast-track powers to help push free-trade proposals such as the 12-nation Trans-Pacific Partnership.

"I would not be doing this trade deal if I did not think it was good for the middle class," Obama said in an interview Tuesday with MSNBC. "When you hear folks make a lot of suggestions about how bad this trade deal is, when you dig into the facts, they are wrong."

Several top Democrats aren't backing down, however. Senate Minority Leader Harry Reid of Nevada told reporters, "I'm not only no, I'm hell no" on Obama's bid for fast-track authority.

Few issues divide Democrats more than trade. Obama, like former President Bill Clinton, supports free trade, but many Democratic lawmakers do not.

Clinton's and Obama's stands — and liberal groups' opposition — pose a dilemma for Hillary Rodham Clinton, the former first lady now seeking the presidency herself. Campaigning Tuesday in New Hampshire, she declined to say whether she supports the Pacific-rim proposal.

"We need to build things, too," Clinton said, taking a pro-manufacturing stance generally embraced by both parties. "We have to do our part in making sure we have the capabilities and skills to be competitive," she said, while getting back to "a much more focused effort, in my opinion, to try to produce those capacities here at home."

Senate Finance Committee member Chuck Schumer, D-N.Y., says the administration must press China to stop manipulating its currency, even though China isn't a party to the Pacific-rim negotiations. "I'm disappointed in the efforts by President Obama," Schumer said.

If a nation keeps its currency value artificially low, it can boost exports by making local products more affordable to foreigners. Economists disagree on whether China still engages in the practice, and the Obama administration says it addresses currency manipulation in the fast-track bill.

Republicans generally support trade pacts. But Obama can't count on them alone to push the fiercely debated bills through the GOP-controlled House and Senate.

"He has to bring Democrats," Rep. Paul Ryan, the Wisconsin Republican who heads the House Ways and Means Committee, said Wednesday.

"This absolutely has to be bipartisan in order to be successful," said Ryan. He said he feels Obama is on the right track on this issue even though he disagrees with the president on many other matters.

Most or all Senate Finance Committee Republicans support fast track. Democratic supporters include Sens. Ron Wyden of Oregon, Maria Cantwell of Washington, Tom Carper of Delaware and Mark Warner of Virginia.

Committee passage would move the bill to the full Senate. The House has yet to vote on fast track this year.

Originally published by Associated Press