President Biden's nominee for the Food and Drug Administration (FDA) on Wednesday picked up a key Democratic endorsement from Sen. Ron Wyden (D-Ore.).

The support of the chair of the Senate Finance Committee is crucial for Robert Califf's potential confirmation in the closely divided Senate. 

“The FDA has an indispensable role in protecting the health and safety of Americans. Americans are counting on the FDA to address serious health issues, from tobacco and e-cigarette use to the ongoing opioid and fentanyl crisis. I am prepared to support Dr. Califf’s nomination so that he can shift the FDA into high gear to take action on these challenges, and I will be watching closely to ensure that happens," Wyden said in a statement.

Last week, Wyden pressed Califf to hold drug companies accountable if they try to abuse the agency's accelerated approval pathway. Califf confirmed in a letter that he will make the issue a priority, which Wyden said was enough to secure his backing. 

“Too many families and taxpayers are paying sky-high prices for drugs that still haven’t been shown to have any clinical benefit, even as companies continue raising their prices. I appreciate Dr. Califf’s timely response to my letter to indicate that this issue will be a high priority," Wyden said. 

Califf, who previously led the FDA from February 2016 to January 2017 under then-President Obama, was confirmed in 2016 by an 89 to 4 vote. But his confirmation this time is uncertain. 

At least five Democrats have already spoken out against Califf, and it's not yet clear if enough Republicans will support him to make up the difference, as anti-abortion groups have been lobbying hard against him.

Susan B. Anthony List said it would “key vote” Califf’s nomination as a result of his work on the abortion drug mifepristone during the Obama administration. Nearly all Republican senators have an A+ from the organization, with the exceptions of Sens. Susan Collins (Maine) and Lisa Murkowski (Alaska). 

Collins and Murkowski joined with Sens. Mitt Romney (Utah) and Richard Burr (N.C.) as the only Republicans to vote for Califf in committee.

Senior White House officials are making bipartisan calls to senators asking for support, as the White House can ill afford to lose a key nomination.

A White House official said Califf has met with nearly 50 senators from both parties, which is among the highest number of meetings of any Biden nominee.