The Trans-Pacific Partnership (TPP) free trade pact could impact whether Rep. Ami Bera (D-CA) wins his re-election bid. Members of his own party are abandoning him over his decision to side with Republicans, over the objections of organized labor, to give President Barack Obama fast-track authority to negotiate the deal.

“He has undermined the trust working people had in him,” AFL-CIO President Richard Trumka told the Sacramento Bee. Bera is facing a challenge from Republican Scott Jones, the Sacramento County sheriff.

Labor unions are staunchly opposed to the TPP, suggesting it will take jobs away from Americans in the face of an increasingly globalized world and marketplace. A Bloomberg Politics poll released last week showed that two-thirds of Americans would prefer having an American-owned factory that employs 1,000 people over a Chinese-owned one that would employ closer to 2,000.

Obama’s TPP bill has been rejected by big labor as well as some conservatives. Both Republican presidential frontrunner Donald Trump and Democratic favorite Hillary Clinton have come out against the TPP, as have challengers Sen. Ted Cruz (R-TX) and Sen. Bernie Sanders (I-VT). Ohio Gov. John Kasich (R) has been supportive, however.

Bera was also criticized for supporting a Republican bill in Congress that would prevent refugees from Syria and Iraq from entering the U.S. unless the head of the FBI, the Secretary of theDepartment of Homeland Security, and the Director of National Intelligence certify that the refugees would not endanger U.S. citizens and America’s national security. He was was among eight Democrats to break with his party and vote in favor of the bill.

Union-supplied workers were part of the reason why Bera, a two-term congressional representative, won reelection in 2014. However, he might not need them this time around, due to backing from free trade supporters like the New Democrat PAC ,which has contributors like Silicon Valley billionaire Sean Parker, Google and venture capitalists.

The Bee notes that Trumka cited a study by the labor-backed Economic Policy Institute showing that in 2015, California lost 227,000 jobs, and Bera’s district lost 2,600 jobs, to 11 TPP nations. Conversely, Carl Guardino, who led the Silicon Valley Leadership Group delegation to Washington last week, reportedly estimates that around 7 million Californians have jobs that in some way depend on trade.

Bera has previously stated that he will decide his position on the TPP by spring. He reportedly noted that he is ultimately seeking a deal that is good for American workers and insisted that “it has to open up exports.”

The issue remains whether the union’s opposition will prove powerful enough to prevent this so-called “establishment” Democrat from winning reelection.

Follow Adelle Nazarian on Twitter @AdelleNaz.