Ohio Sen. Rob Portman scheduled a press call with state reporters in early February to announce surprising news: He would oppose the Trans-Pacific Partnership, the massive trade deal that President Obama’s officials have been negotiating with 11 Pacific countries for years.

Portman’s announcement was surprising, an about-face by one of the most business-friendly Republicans in Congress, who can boast a 92 percent lifetime voting rating from the Chamber of Commerce. He even served as U.S. trade representative under George W. Bush, responsible for propelling the Central American Free Trade Agreement to passage and into law.