A critical aspect of President Barack Obama's economic legacy got a boost on Wednesday when the Senate voted to approve giving him "fast-track" authority to negotiate a sweeping 12-nation trade pact without the threat of Congress adding amendments or filibustering the final deal.
The vote was 60-38. The measure now heads to the president's desk for signature.
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The "fast track" measure ensures Congress' right to vote on a massive trade accord, known as the Trans-Pacific Partnership, between the U.S. and 11 other nations, but blocks legislators from adding amendments that might slow down the measure's progress. The resulting trade pact would be the largest since the North American Free Trade Agreement.
Support for granting the president "fast track" authority created an unlikely alliance between the White House, Senate Republicans and even some Hollywood executives eager to strengthen copyright protections.
The months-long showdown over trade was also the source of acrimonious debate as Democrats and the labor unions, which typically support the party, voiced concerns that the trade deal will cost American jobs and result in lowered middle class wages.
Earlier this month, in a move that was a decided blow to the president's trade agenda, Democratic lawmakers in the House helped undermine legislation aimed at shoring up the administration's ability to negotiate a sweeping multinational trade pact. The series of surprising votes came mere hours after President Obama headed to Capitol Hill earlier that morning in a last-minute effort to try to sway Democratic House members to support his trade agenda — a move that rankled some Democrats.
Well into the debate, in a dramatic turn of events, Democratic Leader Nancy Pelosi announced on the House floor that she would be voting against a measure intended to shield workers who might be adversely affected by the trade deal and the measure giving the president "fast track" authority.
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Fast track ultimately passed as a stand alone bill absent the "Trade Adjustment Assistance" measure intended to shield workers who might be adversely affected by the trade deal.
The Senate will now turn to the worker protection measure which is attached to a measure called the African Growth and Opportunity Act and has overwhelming support in the Senate.
That measure will then go back to the House, where it is expected to pass on Thursday now that Pelosi no longer opposes to the measure. The worker protections measure failed in the House when it was attached to "fast track" earlier this month after Democrats united to defeat the measure in an effort to slow down that provision.
But the moved didn't have the desired effect, as Republican leadership turned around and passed "fast track" as a stand-alone bill, sending it to the Senate for passage.
This article originally appeared on NBCNews.com.