Democrats who voted Thursday afternoon in favor of a controversial trade bill, known as “fast track,” will feel the wrath of some liberal groups.

The bill, known as the Trade Promotion Authority, passed 218-208, with 28 Democrats siding with President Obama and a strong, if unlikely, majority of Republicans. But liberal groups warned they would face a backlash from Democratic voters.

“Democrats who allowed the passage of [the fast track] … should know that we will not lift a finger or raise a penny to protect you when you’re attacked in 2016, we will encourage our progressive allies to join us in leaving you to rot,” said Jim Dean, chair of Democracy for America, “and we will actively search for opportunities to primary you with a real Democrat,”

“Those primaries could happen next year or they could happen in election cycles to come, but, make no mistake, we will make certain that your vote to fast track the destruction of American jobs will be remembered and will haunt you for years to come,” he added. Democracy for America oversees a grassroots membership of 10.1 million.

Erich Pica, president of Friends of the Earth, a national environmental organization, said that he was “profoundly disappointed” with the Democratic leadership. “Sadly, we have come to expect Republicans to sell out the environment for the pursuit of corporate profits,” he said. “But we expect more regard for environmental protection and respect for working families from President Obama and the Democrats who supported this bill.”

The Trade Promotion Authority gives Obama the legal power to negotiate, and then pass to Congress for a straight up-or-down vote, all future free trade deals. That includes the controversial and imminent Trans-Pacific Partnership, which would knit together 12 Pacific Rim nations and 40% of the world’s GDP. Liberals, labor activists and environmentalists have furiously lobbied Democratic politicians in recent months to vote against the fast track on the grounds that it “greases the skids” for the TPP, which they argue will lead to job losses in the U.S., and a degradation of workers’ rights and environmental protections abroad.

But many major liberal heavyweights, including the labor unions, have been unwilling to make Democratic votes on the fast track bill a litmus test. AFL-CIO, for example, said this week that its 2016 endorsements will “not hinge” on how candidates voted on trade.

Stephanie Taylor, the co-founder of Progressive Change Campaign Committee, stopped short of making an ultimatum Thursday, asking instead that Democratic leaders lobby the Senate to vote no on the bill. “Voters need to see that Democratic Party leaders, including Hillary Clinton, are willing to strongly fight corporate interests that seek to hurt workers and everyday families,” she said Thursday. “All presidential candidates should urge the Senate to vote no on fast track.”

Clinton, the Democratic frontrunner, has yet to weigh in on whether she supports either fast track or the Trans-Pacific Partnership. In comments last weekend, she urged the White House to work with Congressional Democrats to strengthen support for American workers—a comment that broke from a strongly pro-trade position in the past.

Senate Majority Leader Mitch McConnell has promised that the bill will pass the Senate.

Get our Politics Newsletter. The headlines out of Washington never seem to slow. Subscribe to The D.C. Brief to make sense of what matters most. Please enter a valid email address. Sign Up Now Check the box if you do not wish to receive promotional offers via email from TIME. You can unsubscribe at any time. By signing up you are agreeing to our Terms of Use and Privacy Policy . This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply. Thank you! For your security, we've sent a confirmation email to the address you entered. Click the link to confirm your subscription and begin receiving our newsletters. If you don't get the confirmation within 10 minutes, please check your spam folder.

Write to Haley Sweetland Edwards at haley.edwards@time.com.