Marty Makary's departure from the Food and Drug Administration may remove one of the Trump administration's lightning rods for controversy.But it won't solve the organizational upheaval and political jockeying that marked much of his 13-month tenure.Why it matters: There's lots of uncertainty around how the Senate will find the bandwidth to confirm another FDA commissioner while it considers President Trump's nominees for Centers for Disease Control and Prevention director and surgeon general.The FDA itself is also facing other key internal vacancies, including for directors of the centers overseeing drugs and biologics.And there are questions about whether a successor will continue efforts to streamline clinical trials and other regulatory actions.Driving the news: On Tuesday, Trump confirmed Makary was out after facing internal criticism for not accommodating some of the president's priorities, as well as complaints from health care investors about unpredictable regulatory decisions that rejected some promising drugs."Marty is a great guy. He was having some difficulty," Trump told reporters, in response to questions about whether he resigned or was fired. He later wrote on Truth Social that the Johns Hopkins physician and researcher "was a hard worker, who was respected by all, and will go on to have an outstanding career in medicine."The task of steering the agency for the moment will fall to Kyle Diamantas, a Florida lawyer and reported friend of Donald Trump Jr. who was heading the FDA's food center.Between the lines: David Mansdoerfer, a senior HHS official in the first Trump administration, wrote on X that Diamantas had the regulatory and legal chops to lead a transition and also was "a good pick for MAHA, and a good pick for business."Possible successors who've been floated include more mainstream figures and veterans from Trump's first administration like former FDA commissioner Stephen Hahn and Brett Giroir, who was briefly acting commissioner.Even before Trump made Makary's exit official, various health interests — from vaping lobbyists to independent physicians to anti-abortion politicians — were calling for a reset. It was a sign of how much surprise policy moves, organizational upheaval and political interference have come to characterize an agency once known for predictability and evidence-based decision-making.Makary didn't deliver on many actions that industry welcomed, and may have ultimately been done in by his management style and hiring choices, Raymond James analyst Chris Meekins wrote in a note.There was considerable drama and controversy around former top vaccine regulator Vinay Prasad and tensions with the White House over Makary's moves to block Trump's vaping agenda — which is seen as key to appealing to young MAGA voters.But Makary had his fans, even among some Democrats in Congress, who praised his independence. "I hope Dr. Makary will inspire others within the Trump administration to grow a spine and put the families of America ahead of blind loyalty to this president," said Sen. Dick Durbin (D-Ill.). John Crowley, CEO of the biotech trade group BIO, said Makary inherited an agency in crisis from sweeping DOGE layoffs, then presided over constant leadership changes and shifting standards for drug approvals. "What we need now is strong, stable and science-driven leadership at the FDA," he said.The intrigue: Any nomination will come before the Senate health committee, whose chairman, Bill Cassidy (R-La), faces a tough primary this weekend against a Trump-endorsed challenger. The political dynamics and ongoing challenges at the agency could mean the administration will take its time putting a name forward. "Finding someone industry welcomes and MAHA does not despise may be a bit of a challenging channel to navigate," Meekins wrote.