Democrats felt comfortable supporting President Donald Trump’s renegotiated trade agreement with Canada and Mexico because labor unions, mostly, did.

The unions said the new U.S.-Mexico-Canada Agreement would be an improvement over its predecessor, the North American Free Trade Agreement.

Still, environmentalists opposed it. Wenonah Hauter, the executive director of Food & Water Action, said the deal “spells disaster for food safety, air and water quality, and climate change” because it asks little of the parties by way of conservation.

When the Senate voted on Jan. 16 to approve the deal, the vote was 89-10, and many of the opponents put their concerns for the environment ahead of the economic benefits the deal provides their home states.

The most notable was Kamala Harris. More people in her state, California, have jobs because of trade with Canada and Mexico than in any other. Even so, the Democrat broke with her fellow senator, Dianne Feinstein, and opposed the deal. She said in a statement that she appreciated the efforts of Speaker Nancy Pelosi and labor union leaders to improve the agreement. But Harris said the pact’s lack of attention to the environment was unacceptable.

“By not addressing climate change, the USMCA fails to meet the crises of this moment,” she said.