Maria Cantwell of Washington, the top Democrat on the Commerce Committee, said Friday she'll oppose Stephen Dickson's nomination.
A spokesman for Trump says the White House has complete confidence Dickson will be confirmed. Republicans hold majorities in the Senate and the Commerce Committee, which will vote on the nomination Wednesday.
A pilot suing Delta says after she reported safety issues to Dickson in 2016, the airline retaliated by referring her for a psychiatric examination, which grounded her for more than a year. Dickson was Delta's senior vice president of flight operations at the time.
Cantwell says Delta's culture under Dickson allowed retaliation.