President Joe Biden’s nominee to be the next labor secretary, Julie Su, will testify to 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 will vote for Su’s nomination ahead of her confirmation hearing before the Senate Health, Education, Labor and Pensions Committee. Biden in February picked Su, a civil rights attorney and the current deputy labor secretary, to replace Marty Walsh, the former mayor of Boston, to lead the Department of Labor.

The daughter of an immigrant mother who arrived on a cargo ship, Su 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 that “she’s committed to making sure that dream is in reach for every American.”

Su was previously confirmed as the deputy labor secretary, but has faced opposition from business groups critical of her record leading California’s labor department. They point to her support of an overturned California law that would have required app-based ride hailing and delivery companies like Uber and Lyft, as well as trucking businesses, to treat their workers as employees, providing benefits like paid sick leave and unemployment insurance, rather than independent contractors.

Su has also faced blame for problems at the California Labor and Workforce Development Agency during the coronavirus pandemic when unprecedented numbers of people applying for unemployment benefits faced long wait times and the state potentially paid out billions of dollars in fraudulent claims.

Feinstein’s Absence Creates Challenge

Democratic Sens. Joe Manchin, Jon Tester and Mark Kelly and Sen. Kyrsten Sinema, an independent, all declined to say whether they would vote for her confirmation this week. Democrats cannot afford to lose more than a couple votes in a Senate divided 51-49. Sen. Dianne Feinstein, D-Calif., is also recovering from shingles in California, with no firm return date.

Manchin repeatedly declined to comment on Su’s nomination this week; Tester said he would meet with her after the meeting to “make sure she’s still right”; Kelly said he did not have concerns about her record but added he does not preview his votes; Sinema said through a spokeswoman that she does not preview votes.

Su was confirmed by the Senate to her current role in 2021 by a 50–47 vote.

Republican Sen. Lisa Murkowski said she voted against Su’s confirmation in 2021 because of “how she had handled the unemployment compensation issues in the state of California.”

Top Democrats, meanwhile, have signaled their support for Su with meetings at the Capitol this week.

At a meeting with Su on Monday, Sen. Tim Kaine, a Virginia Democrat, pointed to her work on job growth and said, “She’s done a good job and I think she’s got a two-year track record that is strong.”

Late last year, Su was central to negotiations between labor and freight rail companies and helped avoid an economically debilitating strike. She has also led efforts to crack down on wage theft.