Dealing a major blow to President Barack Obama’s second-term agenda, House Democrats voted to derail a bill that would help him secure a massive free trade deal with 11 other Pacific Rim nations.

In a surprisingly lopsided defeat, the House rejected a measure that offered financial assistance to workers who lost their jobs because of free trade, a key component of a bill that would give the president fast-track trade authority. Despite the president’s last-minute appearance on Capitol Hill Friday morning to build support for the bill, a critical mass of liberal Democrats and conservative Republicans united against him, and the measure received just 126 votes. The decisive blow came when House Minority Leader Nancy Pelosi (D-Calif.) broke her silence on Friday and came out against the emerging trade deal known as the Trans-Pacific Partnership (TPP). “Whatever the deal is with other countries, we want a better deal for America’s workers,” she said. “I will be voting to slow down fast-track.”

Although Republican leaders in the House and Senate may make another pass at the legislation at a later date, the vote has for the moment dashed hopes for an international agreement on TPP. The historic trade deal — the most significant since NAFTA — would remove trade barriers between 12 countries on both sides of the Pacific whose economies comprise some 40 percent of the world’s total GDP. The TPP is a central feature of the president’s pivot to Asia — a policy that has struggled to find traction as crises have flared up in the Middle East — and one that he has expended considerable political capital to push through.

Prior to the vote, it was clear that even the president’s rare last-minute visit to the Hill hadn’t swayed members of his own party. “I don’t think you ever nail anything down around here,” Obama told reporters who asked about the vote. “It’s always moving.”

Obama had argued that the TPP would counterbalance China’s ability to shape trade policy in the region. “If we are not there helping to shape the rules of the road, then U.S. businesses and U.S. workers are going to be cut out, because there’s a pretty big country there, called China, that is growing fast, has great gravitational pull, and often operates with different sets of rules,” Obama said in an interview on National Public Radio’s “Marketplace.”

The White House also asserted that the deal would create export-focused American jobs. Critics of the deal, led by the American labor movement, argued that the deal would lead to widespread U.S. job losses and reward countries with abysmal human-rights records.

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