Democratic control of the House could give labor unions more power to voice their concerns over the renegotiated NAFTA deal, but many of the groups have so far been shy to publicly criticize the agreement.

Maybe that’s because labor organizations understand some compromises will be necessary to get to ratification, political observers told Bloomberg Law.

NAFTA 2.0—or the United States–Mexico–Canada Agreement—includes some labor protections such as the freedom to unionize, the right to bargain collectively, and minimum wages. The proposed pact also retools a controversial model for resolving pact violations, but some labor advocates are still concerned about enforcement.

“We...