The Senate is poised to hand President Barack Obama a major victory with final passage of "fast track" authority to negotiate trade deals.
Doing so would cap a remarkable turnabout for an initiative that House Democrats nearly killed earlier this month.
Opening Senate debate on Wednesday, Senate Majority Leader Mitch McConnell, R-Ky., a frequent Obama antagonist, credited the president and Democrats who joined the GOP on the bipartisan measure long sought by the nation's chief executive.
"We were really pleased to see President Obama pursue an idea we've long believed in," McConnell said. "We thank him for his efforts to help us pass a bill to advance it."
Unions and most congressional Democrats say free-trade deals cost U.S. jobs and reward countries that pollute and mistreat workers. But Obama and most Republican leaders say U.S. products must reach broader markets.
The Senate also plans to vote on three other trade-related bills. The most important would extend a job retraining program for workers displaced by international trade. That program would require House approval, too.
Senate approval of fast track on Wednesday would boost Obama's hopes for a 12-nation Pacific-rim trade agreement. It's key to his effort to expand U.S. influence in Asia. Negotiating parties include Japan, Malaysia, Mexico and Canada.
If granted fast-track authority, Obama would ask Congress to ratify the Pacific deal after the public has weeks or months to study it.
Some anti-trade groups say they will strongly oppose the Pacific pact. Others seem more resigned to the likelihood of new U.S. trade agreements in Obama's final months in office.