Cassidy is expected to challenge RFK Jr. on his vaccine skepticism and views on public health in today's confirmation hearing.

BATON ROUGE, La. (AP) — Sen. Bill Cassidy has emerged as a central figure in the confirmation of Robert F. Kennedy Jr., whose nomination to health and human services secretary poses an equally consequential moment for the second-term Republican facing an uncertain political future in Louisiana.

Robert F. Kennedy Jr. goes before two two U.S. Senate hearings in his quest to head the nation's health department. Louisiana Sen. Bill Cassidy, a doctor, sits on both.