Key Senate Democrats won't say whether they'll back Biden nominee for labor secretary Julie Su

President Joe Biden's nominee to be the next labor secretary, Julie Su, will be testifying before the Senate Thursday with key Democrats unwilling to voice support for her confirmation, creating uncertainty about her prospects in the narrowly divided chamber.

A handful of moderate Democrats have not publicly stated whether they'll vote for Su's nomination ahead of her confirmation hearing before the Senate Health, Education, Labor and Pensions Committee. Biden in February picked Su to replace Marty Walsh, the former mayor of Boston, as labor secretary.

Su, a civil rights attorney and the current deputy labor secretary, is the daughter of an immigrant mother who arrived on a cargo ship. She would be the first Asian American in the Biden administration to serve in the Cabinet at the secretary level. Biden called her path proof of the "American dream" and said that "she's committed to making sure that dream is in reach for every American."